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Python is a
high-level High-level and low-level, as technical terms, are used to classify, describe and point to specific goals of a systematic operation; and are applied in a wide range of contexts, such as, for instance, in domains as widely varied as computer scienc ...
,
general-purpose programming language In computer software, a general-purpose programming language (GPL) is a programming language for building software in a wide variety of application domains. Conversely, a domain-specific programming language is used within a specific area. For exam ...
. Its design philosophy emphasizes
code readability Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as anal ...
with the use of significant indentation. Python is dynamically-typed and garbage-collected. It supports multiple
programming paradigm Programming paradigms are a way to classify programming languages based on their features. Languages can be classified into multiple paradigms. Some paradigms are concerned mainly with implications for the execution model of the language, suc ...
s, including
structured Structuring, also known as smurfing in banking jargon, is the practice of executing financial transactions such as making bank deposits in a specific pattern, calculated to avoid triggering financial institutions to file reports required by law ...
(particularly procedural),
object-oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of " objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of p ...
and
functional programming In computer science, functional programming is a programming paradigm where programs are constructed by applying and composing functions. It is a declarative programming paradigm in which function definitions are trees of expressions that ...
. It is often described as a "batteries included" language due to its comprehensive standard library.
Guido van Rossum Guido van Rossum (; born 31 January 1956) is a Dutch programmer best known as the creator of the Python programming language, for which he was the "benevolent dictator for life" (BDFL) until he stepped down from the position on 12 July 2018 ...
began working on Python in the late 1980s as a successor to the ABC programming language and first released it in 1991 as Python 0.9.0. Python 2.0 was released in 2000 and introduced new features such as
list comprehension A list comprehension is a syntactic construct available in some programming languages for creating a list based on existing lists. It follows the form of the mathematical ''set-builder notation'' (''set comprehension'') as distinct from the use of ...
s, cycle-detecting garbage collection, reference counting, and
Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...
support. Python 3.0, released in 2008, was a major revision that is not completely
backward-compatible Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially in ...
with earlier versions. Python 2 was discontinued with version 2.7.18 in 2020. Python consistently ranks as one of the most popular programming languages.


History

Python was conceived in the late 1980s by
Guido van Rossum Guido van Rossum (; born 31 January 1956) is a Dutch programmer best known as the creator of the Python programming language, for which he was the "benevolent dictator for life" (BDFL) until he stepped down from the position on 12 July 2018 ...
at
Centrum Wiskunde & Informatica The (abbr. CWI; English: "National Research Institute for Mathematics and Computer Science") is a research centre in the field of mathematics and theoretical computer science. It is part of the institutes organization of the Dutch Research Co ...
(CWI) in the
Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...
as a successor to the ABC programming language, which was inspired by
SETL SETL (SET Language) is a very high-level programming language based on the mathematical theory of sets. It was originally developed by (Jack) Jacob T. Schwartz at the New York University (NYU) Courant Institute of Mathematical Sciences in the ...
, capable of
exception handling In computing and computer programming, exception handling is the process of responding to the occurrence of ''exceptions'' – anomalous or exceptional conditions requiring special processing – during the execution of a program. In general, an ...
(from the start plus new capabilities in Python 3.11) and interfacing with the
Amoeba An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudop ...
operating system. Its implementation began in December 1989. Van Rossum shouldered sole responsibility for the project, as the lead developer, until 12 July 2018, when he announced his "permanent vacation" from his responsibilities as Python's " benevolent dictator for life", a title the Python community bestowed upon him to reflect his long-term commitment as the project's chief decision-maker. In January 2019, active Python core developers elected a five-member Steering Council to lead the project. Python 2.0 was released on 16 October 2000, with many major new features. Python 3.0, released on 3 December 2008, with many of its major features backported to Python 2.6.x and 2.7.x. Releases of Python 3 include the 2to3 utility, which automates the translation of Python 2 code to Python 3. Python 2.7's end-of-life was initially set for 2015, then postponed to 2020 out of concern that a large body of existing code could not easily be forward-ported to Python 3. No further security patches or other improvements will be released for it. Currently only 3.7 and later are supported. In 2021, Python 3.9.2 and 3.8.8 were expedited as all versions of Python (including 2.7) had security issues leading to possible
remote code execution In computer security, arbitrary code execution (ACE) is an attacker's ability to run any commands or code of the attacker's choice on a target machine or in a target process. An arbitrary code execution vulnerability is a security flaw in softwar ...
and web cache poisoning. In 2022, Python 3.10.4 and 3.9.12 were expedited and 3.8.13, and 3.7.13, because of many security issues. When Python 3.9.13 was released in May 2022, it was announced that the 3.9 series (joining the older series 3.8 and 3.7) will only receive security fixes going forward. On September 7, 2022, four new releases were made due to a potential
denial-of-service attack In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host conn ...
: 3.10.7, 3.9.14, 3.8.14, and 3.7.14. Python 3.11.0 is the current stable release and among the notable changes from 3.10 are that it is 10–60% faster and significantly improved error reporting. Python 3.12 (alpha 2) has improved error messages.


Removals from Python

The deprecated smtpd module has been removed from Python 3.12 (alpha). And a number of other old, broken and deprecated functions (e.g. from unittest module), classes and methods have been removed. The deprecated wstr and wstr_ length members of the C implementation of
Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...
objects were removed, to make
UTF-8 UTF-8 is a variable-width encoding, variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit'' ...
the default in later Python versions. Historically, Python 3 also made changes from Python 2, e.g. changed the division operator.


Design philosophy and features

Python is a
multi-paradigm programming language Programming paradigms are a way to classify programming languages based on their features. Languages can be classified into multiple paradigms. Some paradigms are concerned mainly with implications for the execution model of the language, suc ...
.
Object-oriented programming Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pr ...
and structured programming are fully supported, and many of their features support functional programming and
aspect-oriented programming In computing, aspect-oriented programming (AOP) is a programming paradigm that aims to increase modularity by allowing the separation of cross-cutting concerns. It does so by adding behavior to existing code (an advice) ''without'' modifying th ...
(including
metaprogramming Metaprogramming is a programming technique in which computer programs have the ability to treat other programs as their data. It means that a program can be designed to read, generate, analyze or transform other programs, and even modify itself ...
and
metaobject In computer science, a metaobject is an object that manipulates, creates, describes, or implements objects (including itself). The object that the metaobject pertains to is called the base object. Some information that a metaobject might define incl ...
s). Many other paradigms are supported via extensions, including design by contract and
logic programming Logic programming is a programming paradigm which is largely based on formal logic. Any program written in a logic programming language is a set of sentences in logical form, expressing facts and rules about some problem domain. Major logic pro ...
. Python uses
dynamic typing In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms are various constructs of a computer progra ...
and a combination of reference counting and a cycle-detecting garbage collector for
memory management Memory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when ...
. It uses dynamic name resolution (
late binding In computing, late binding or dynamic linkage—though not an identical process to dynamically linking imported code libraries—is a computer programming mechanism in which the method being called upon an object, or the function being called ...
), which binds method and variable names during program execution. Its design offers some support for functional programming in the Lisp tradition. It has functions;
list comprehension A list comprehension is a syntactic construct available in some programming languages for creating a list based on existing lists. It follows the form of the mathematical ''set-builder notation'' (''set comprehension'') as distinct from the use of ...
s, dictionaries, sets, and
generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...
expressions. The standard library has two modules ( and ) that implement functional tools borrowed from
Haskell Haskell () is a general-purpose, statically-typed, purely functional programming language with type inference and lazy evaluation. Designed for teaching, research and industrial applications, Haskell has pioneered a number of programming lan ...
and Standard ML. Its core philosophy is summarized in the document ''The
Zen of Python The Zen of Python is a collection of 19 "guiding principles" for writing computer programs that influence the design of the Python programming language. Software engineer Tim Peters wrote this set of principles and posted it on the Python mailing ...
'' (''PEP 20''), which includes
aphorism An aphorism (from Greek ἀφορισμός: ''aphorismos'', denoting 'delimitation', 'distinction', and 'definition') is a concise, terse, laconic, or memorable expression of a general truth or principle. Aphorisms are often handed down by ...
s such as: * Beautiful is better than ugly. * Explicit is better than implicit. * Simple is better than complex. * Complex is better than complicated. * Readability counts. Rather than building all of its functionality into its core, Python was designed to be highly
extensible Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be t ...
via modules. This compact modularity has made it particularly popular as a means of adding programmable interfaces to existing applications. Van Rossum's vision of a small core language with a large standard library and easily extensible interpreter stemmed from his frustrations with
ABC ABC are the first three letters of the Latin script known as the alphabet. ABC or abc may also refer to: Arts, entertainment, and media Broadcasting * American Broadcasting Company, a commercial U.S. TV broadcaster ** Disney–ABC Television ...
, which espoused the opposite approach. Python strives for a simpler, less-cluttered syntax and grammar while giving developers a choice in their coding methodology. In contrast to
Perl Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was offic ...
's "
there is more than one way to do it There's more than one way to do it (TMTOWTDI or TIMTOWTDI, pronounced ''Tim Toady'') is a Perl programming motto. The language was designed with this idea in mind, in that it “doesn't try to tell the programmer how to program.” As proponents of ...
" motto, Python embraces a "there should be one—and preferably only one—obvious way to do it" philosophy.
Alex Martelli Alex Martelli (born October 5, 1955) is an Italian computer engineer and Fellow of the Python Software Foundation. Since early 2005, he works for Google, Inc. in Mountain View, California, for the first few years as "Über Tech Lead," then as "Se ...
, a
Fellow A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher education ...
at the
Python Software Foundation The Python Software Foundation (PSF) is an American nonprofit organization devoted to the Python programming language, launched on March 6, 2001. The mission of the foundation is to foster development of the Python community and is responsible for ...
and Python book author, wrote: "To describe something as 'clever' is ''not'' considered a compliment in the Python culture." Python's developers strive to avoid
premature optimization In computer science, program optimization, code optimization, or software optimization, is the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources. In general, a computer program may be o ...
and reject patches to non-critical parts of the
CPython CPython is the reference implementation of the Python programming language. Written in C and Python, CPython is the default and most widely used implementation of the Python language. CPython can be defined as both an interpreter and a compi ...
reference implementation that would offer marginal increases in speed at the cost of clarity. When speed is important, a Python programmer can move time-critical functions to extension modules written in languages such as C; or use
PyPy PyPy () is an implementation of the Python programming language. PyPy often runs faster than the standard implementation CPython because PyPy uses a just-in-time compiler. Most Python code runs well on PyPy except for code that depends on CPyth ...
, a
just-in-time compiler In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compilation during execution of a program (at run time) rather than before execution. This may cons ...
.
Cython Cython () is a programming language that aims to be a superset of the Python programming language, designed to give C-like performance with code that is written mostly in Python with optional additional C-inspired syntax. Cython is a compiled ...
is also available, which translates a Python script into C and makes direct C-level API calls into the Python interpreter. Python's developers aim for it to be fun to use. This is reflected in its name—a tribute to the British comedy group Monty Python—and in occasionally playful approaches to tutorials and reference materials, such as examples that refer to spam and eggs (a reference to a Monty Python sketch) instead of the standard foo, and bar. A common
neologism A neologism Greek νέο- ''néo''(="new") and λόγος /''lógos'' meaning "speech, utterance"] is a relatively recent or isolated term, word, or phrase that may be in the process of entering common use, but that has not been fully accepted int ...
in the Python community is ''pythonic'', which has a wide range of meanings related to program style. "Pythonic" code may use Python idioms well, be natural or show fluency in the language, or conform with Python's minimalist philosophy and emphasis on readability. Code that is difficult to understand or reads like a rough transcription from another programming language is called ''unpythonic''. Python users and admirers, especially those considered knowledgeable or experienced, are often referred to as ''Pythonistas''.


Syntax and semantics

Python is meant to be an easily readable language. Its formatting is visually uncluttered and often uses English keywords where other languages use punctuation. Unlike many other languages, it does not use curly bracket programming language, curly brackets to delimit blocks, and semicolons after statements are allowed but rarely used. It has fewer syntactic exceptions and special cases than C or Pascal.


Indentation

Python uses whitespace indentation, rather than curly bracket programming language, curly brackets or keywords, to delimit blocks. An increase in indentation comes after certain statements; a decrease in indentation signifies the end of the current block. Thus, the program's visual structure accurately represents its semantic structure. This feature is sometimes termed the
off-side rule A computer programming language is said to adhere to the off-side rule of syntax if blocks in that language are expressed by their indentation. The term was coined by Peter Landin, possibly as a pun on the offside rule in association football ...
. Some other languages use indentation this way; but in most, indentation has no semantic meaning. The recommended indent size is four spaces.


Statements and control flow

Python's
statements Statement or statements may refer to: Common uses *Statement (computer science), the smallest standalone element of an imperative programming language *Statement (logic), declarative sentence that is either true or false *Statement, a declarative ...
include: * The
assignment Assignment, assign or The Assignment may refer to: * Homework * Sex assignment * The process of sending National Basketball Association players to its development league; see Computing * Assignment (computer science), a type of modification to ...
statement, using a single equals sign = * The if statement, which conditionally executes a block of code, along with else and elif (a contraction of else-if) * The for statement, which iterates over an iterable object, capturing each element to a local variable for use by the attached block * The while statement, which executes a block of code as long as its condition is true * The
try Try or TRY may refer to: Music Albums * ''Try!'', an album by the John Mayer Trio * ''Try'' (Bebo Norman album) (2014) Songs * "Try" (Blue Rodeo song) (1987) * "Try" (Colbie Caillat song) (2014) * "Try" (Nelly Furtado song) (2004) * " Try (Ju ...
statement, which allows exceptions raised in its attached code block to be caught and handled by except clauses (or new syntax except* in Python 3.11 for exception groups); it also ensures that clean-up code in a finally block is always run regardless of how the block exits * The raise statement, used to raise a specified exception or re-raise a caught exception * The class statement, which executes a block of code and attaches its local namespace to a
class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...
, for use in object-oriented programming * The def statement, which defines a
function Function or functionality may refer to: Computing * Function key, a type of key on computer keyboards * Function model, a structured representation of processes in a system * Function object or functor or functionoid, a concept of object-oriente ...
or
method Method ( grc, μέθοδος, methodos) literally means a pursuit of knowledge, investigation, mode of prosecuting such inquiry, or system. In recent centuries it more often means a prescribed process for completing a task. It may refer to: *Scien ...
* The
with With or WITH may refer to: * With, a preposition in English * Carl Johannes With (1877–1923), Danish doctor and arachnologist * With (character), a character in ''D. N. Angel'' * ''With'' (novel), a novel by Donald Harrington * ''With'' (album ...
statement, which encloses a code block within a context manager (for example, acquiring a
lock Lock(s) may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance *Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainment * ''Lock ...
before it is run, then releasing the lock; or opening and closing a
file File or filing may refer to: Mechanical tools and processes * File (tool), a tool used to ''remove'' fine amounts of material from a workpiece **Filing (metalworking), a material removal process in manufacturing ** Nail file, a tool used to gent ...
), allowing resource-acquisition-is-initialization (RAII)-like behavior and replacing a common try/finally idiom * The
break Break or Breaks or The Break may refer to: Time off from duties * Recess (break), time in which a group of people is temporarily dismissed from its duties * Break (work), time off during a shift/recess ** Coffee break, a short mid-morning res ...
statement, which exits a loop * The continue statement, which skips the rest of the current iteration and continues with the next * The del statement, which removes a variable—deleting the reference from the name to the value, and producing an error if the variable is referred to before it is redefined * The pass statement, serving as a NOP, syntactically needed to create an empty code block * The
assert Assertion or assert may refer to: Computing * Assertion (software development), a computer programming technique * assert.h, a header file in the standard library of the C programming language * Assertion definition language, a specification lang ...
statement, used in debugging to check for conditions that should apply * The yield statement, which returns a value from a
generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...
function (and also an operator); used to implement
coroutine Coroutines are computer program components that generalize subroutines for non-preemptive multitasking, by allowing execution to be suspended and resumed. Coroutines are well-suited for implementing familiar program components such as cooperative ...
s * The return statement, used to return a value from a function * The import statement, used to import modules whose functions or variables can be used in the current program The assignment statement (=) binds a name as a
reference Reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said to ''refer to'' the second object. It is called a '' name'' ...
to a separate, dynamically-allocated
object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an ...
. Variables may subsequently be rebound at any time to any object. In Python, a variable name is a generic reference holder without a fixed data type; however, it always refers to ''some'' object with a type. This is called
dynamic typing In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms are various constructs of a computer progra ...
—in contrast to
statically-typed In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms are various constructs of a computer progra ...
languages, where each variable may contain only a value of a certain type. Python does not support
tail call In computer science, a tail call is a subroutine call performed as the final action of a procedure. If the target of a tail is the same subroutine, the subroutine is said to be tail recursive, which is a special case of direct recursion. Tail recur ...
optimization or
first-class continuations In computer science, a continuation is an abstract representation of the control state of a computer program. A continuation implements ( reifies) the program control state, i.e. the continuation is a data structure that represents the computati ...
, and, according to Van Rossum, it never will. However, better support for
coroutine Coroutines are computer program components that generalize subroutines for non-preemptive multitasking, by allowing execution to be suspended and resumed. Coroutines are well-suited for implementing familiar program components such as cooperative ...
-like functionality is provided by extending Python's generators. Before 2.5, generators were lazy
iterator In computer programming, an iterator is an object that enables a programmer to traverse a container, particularly lists. Various types of iterators are often provided via a container's interface. Though the interface and semantics of a given iterat ...
s; data was passed unidirectionally out of the generator. From Python 2.5 on, it is possible to pass data back into a generator function; and from version 3.3, it can be passed through multiple stack levels.


Expressions

Python's expressions include: * The +, -, and * operators for mathematical addition, subtraction, and multiplication are similar to other languages, but the behavior of division differs. There are two types of divisions in Python:
floor division Division is one of the four basic operations of arithmetic, the ways that numbers are combined to make new numbers. The other operations are addition, subtraction, and multiplication. At an elementary level the division of two natural numb ...
(or integer division) // and floating-point/division. Python uses the ** operator for exponentiation. * Python uses the + operator for string concatenation. Python uses the * operator for duplicating a string a specified number of times. * The @ infix operator. It is intended to be used by libraries such as NumPy for
matrix multiplication In mathematics, particularly in linear algebra, matrix multiplication is a binary operation that produces a matrix from two matrices. For matrix multiplication, the number of columns in the first matrix must be equal to the number of rows in the s ...
. * The syntax :=, called the "walrus operator", was introduced in Python 3.8. It assigns values to variables as part of a larger expression. * In Python,

compares by value. Python's is operator may be used to compare object identities (comparison by reference), and comparisons may be chained—for example, . * Python uses and, or, and not as boolean operators. * Python has a type of expression called a ''
list comprehension A list comprehension is a syntactic construct available in some programming languages for creating a list based on existing lists. It follows the form of the mathematical ''set-builder notation'' (''set comprehension'') as distinct from the use of ...
'', as well as a more general expression called a ''
generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...
expression''. * Anonymous functions are implemented using
lambda expressions Lambda expression may refer to: *Lambda expression in computer programming, also called an anonymous function, is a defined function not bound to an identifier. * Lambda expression in lambda calculus, a formal system in mathematical logic and ...
; however, there may be only one expression in each body. * Conditional expressions are written as (different in order of operands from the c ? x : y operator common to many other languages). * Python makes a distinction between
lists A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby unio ...
and
tuple In mathematics, a tuple is a finite ordered list (sequence) of elements. An -tuple is a sequence (or ordered list) of elements, where is a non-negative integer. There is only one 0-tuple, referred to as ''the empty tuple''. An -tuple is defi ...
s. Lists are written as , are mutable, and cannot be used as the keys of dictionaries (dictionary keys must be immutable in Python). Tuples, written as , are immutable and thus can be used as keys of dictionaries, provided all of the tuple's elements are immutable. The + operator can be used to concatenate two tuples, which does not directly modify their contents, but produces a new tuple containing the elements of both. Thus, given the variable t initially equal to , executing first evaluates , which yields , which is then assigned back to t—thereby effectively "modifying the contents" of t while conforming to the immutable nature of tuple objects. Parentheses are optional for tuples in unambiguous contexts. * Python features ''sequence unpacking'' where multiple expressions, each evaluating to anything that can be assigned (to a variable, writable property, etc.) are associated in an identical manner to that forming tuple literals—and, as a whole, are put on the left-hand side of the equal sign in an assignment statement. The statement expects an ''iterable'' object on the right-hand side of the equal sign that produces the same number of values as the provided writable expressions; when iterated through them, it assigns each of the produced values to the corresponding expression on the left. * Python has a "string format" operator % that functions analogously to
printf The printf format string is a control parameter used by a class of functions in the input/output libraries of C and many other programming languages. The string is written in a simple template language: characters are usually copied literal ...
format strings in C—e.g. evaluates to "spam=blah eggs=2". In Python 2.6+ and 3+, this was supplemented by the format() method of the str class, e.g. . Python 3.6 added "f-strings": . * Strings in Python can be
concatenated In formal language theory and computer programming, string concatenation is the operation of joining character strings end-to-end. For example, the concatenation of "snow" and "ball" is "snowball". In certain formalisations of concatenat ...
by "adding" them (with the same operator as for adding integers and floats), e.g. returns "spameggs". If strings contain numbers, they are added as strings rather than integers, e.g. returns "22". * Python has various
string literal A string literal or anonymous string is a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally " bracketed delimiters", as in x = "foo", where "foo" is a string ...
s: ** Delimited by single or double quote marks; unlike in
Unix shell A Unix shell is a command-line Interpreter (computing), interpreter or shell (computing), shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting langua ...
s,
Perl Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was offic ...
, and Perl-influenced languages, single and double quote marks work the same. Both use the backslash (\) as an
escape character In computing and telecommunication, an escape character is a character (computing), character that invokes an alternative interpretation on the following characters in a character sequence. An escape character is a particular case of metacharac ...
. String interpolation became available in Python 3.6 as "formatted string literals". ** Triple-quoted (beginning and ending with three single or double quote marks), which may span multiple lines and function like
here document In computing, a here document (here-document, here-text, heredoc, hereis, here-string or here-script) is a file literal or input stream literal: it is a section of a source code file that is treated as if it were a separate file. The term is also ...
s in shells, Perl, and
Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called ...
. **
Raw string A string literal or anonymous string is a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally " bracketed delimiters", as in x = "foo", where "foo" is a strin ...
varieties, denoted by prefixing the string literal with r. Escape sequences are not interpreted; hence raw strings are useful where literal backslashes are common, such as
regular expression A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...
s and
Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
-style paths. (Compare "@-quoting" in C#.) * Python has
array index In computer science, an array is a data structure consisting of a collection of ''elements'' (values or variables), each identified by at least one ''array index'' or ''key''. An array is stored such that the position of each element can be co ...
and
array slicing In computer programming, array slicing is an operation that extracts a subset of elements from an array and packages them as another array, possibly in a different dimension from the original. Common examples of array slicing are extracting a su ...
expressions in lists, denoted as a ey/code>, or . Indexes are zero-based, and negative indexes are relative to the end. Slices take elements from the ''start'' index up to, but not including, the ''stop'' index. The third slice parameter called ''step'' or ''stride'', allows elements to be skipped and reversed. Slice indexes may be omitted—for example, returns a copy of the entire list. Each element of a slice is a
shallow copy In object-oriented programming, object copying is creating a copy of an existing object, a unit of data in object-oriented programming. The resulting object is called an ''object copy'' or simply ''copy'' of the original object. Copying is basic bu ...
. In Python, a distinction between expressions and statements is rigidly enforced, in contrast to languages such as
Common Lisp Common Lisp (CL) is a dialect of the Lisp programming language, published in ANSI standard document ''ANSI INCITS 226-1994 (S20018)'' (formerly ''X3.226-1994 (R1999)''). The Common Lisp HyperSpec, a hyperlinked HTML version, has been derived fro ...
,
Scheme A scheme is a systematic plan for the implementation of a certain idea. Scheme or schemer may refer to: Arts and entertainment * ''The Scheme'' (TV series), a BBC Scotland documentary series * The Scheme (band), an English pop band * ''The Schem ...
, or
Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called ...
. This leads to duplicating some functionality. For example: *
List comprehensions A list comprehension is a syntactic construct available in some programming languages for creating a list based on existing lists. It follows the form of the mathematical ''set-builder notation'' (''set comprehension'') as distinct from the use of ...
vs. for-loops * Conditional expressions vs. if blocks * The eval() vs. exec() built-in functions (in Python 2, exec is a statement); the former is for expressions, the latter is for statements Statements cannot be a part of an expression—so list and other comprehensions or
lambda expressions Lambda expression may refer to: *Lambda expression in computer programming, also called an anonymous function, is a defined function not bound to an identifier. * Lambda expression in lambda calculus, a formal system in mathematical logic and ...
, all being expressions, cannot contain statements. A particular case is that an assignment statement such as cannot form part of the conditional expression of a conditional statement. This has the advantage of avoiding a classic C error of mistaking an assignment operator = for an equality operator

in conditions: is syntactically valid (but probably unintended) C code, but causes a syntax error in Python.


Methods

Methods Method ( grc, μέθοδος, methodos) literally means a pursuit of knowledge, investigation, mode of prosecuting such inquiry, or system. In recent centuries it more often means a prescribed process for completing a task. It may refer to: *Scien ...
on objects are functions attached to the object's class; the syntax is, for normal methods and functions,
syntactic sugar In computer science, syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. It makes the language "sweeter" for human use: things can be expressed more clearly, more concisely, or in an ...
for . Python methods have an explicit
self The self is an individual as the object of that individual’s own reflective consciousness. Since the ''self'' is a reference by a subject to the same subject, this reference is necessarily subjective. The sense of having a self—or ''selfhoo ...
parameter to access instance data, in contrast to the implicit self (or this) in some other object-oriented programming languages (e.g.,
C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...
, Java,
Objective-C Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTS ...
,
Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called ...
). Python also provides methods, often called ''dunder methods'' (due to their names beginning and ending with double-underscores), to allow user-defined classes to modify how they are handled by native operations including length, comparison, in
arithmetic operations Arithmetic () is an elementary part of mathematics that consists of the study of the properties of the traditional operations on numbers—addition, subtraction, multiplication, division, exponentiation, and extraction of roots. In the 19th ce ...
and type conversion.


Typing

Python uses
duck typing Duck typing in computer programming is an application of the duck test—"If it walks like a duck and it quacks like a duck, then it must be a duck"—to determine whether an object can be used for a particular purpose. With nominative ty ...
and has typed objects but untyped variable names. Type constraints are not checked at
compile time In computer science, compile time (or compile-time) describes the time window during which a computer program is compiled. The term is used as an adjective to describe concepts related to the context of program compilation, as opposed to concept ...
; rather, operations on an object may fail, signifying that it is not of a suitable type. Despite being
dynamically typed In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms are various constructs of a computer progra ...
, Python is strongly typed, forbidding operations that are not well-defined (for example, adding a number to a string) rather than silently attempting to make sense of them. Python allows programmers to define their own types using classes, most often used for
object-oriented programming Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pr ...
. New instances of classes are constructed by calling the class (for example, or ), and the classes are instances of the
metaclass In object-oriented programming, a metaclass is a class whose instances are classes. Just as an ordinary class defines the behavior of certain objects, a metaclass defines the behavior of certain classes and their instances. Not all object-oriente ...
type (itself an instance of itself), allowing metaprogramming and
reflection Reflection or reflexion may refer to: Science and technology * Reflection (physics), a common wave phenomenon ** Specular reflection, reflection from a smooth surface *** Mirror image, a reflection in a mirror or in water ** Signal reflection, in ...
. Before version 3.0, Python had two kinds of classes (both using the same syntax): ''old-style'' and ''new-style'', current Python versions only support the semantics new style. The long-term plan is to support
gradual typing Gradual typing is a type system in which some variable (computer science), variables and expressions may be given types and the correctness of the typing is checked at compile time (which is static typing) and some expressions may be left untyped ...
. Python's syntax allows specifying static types, but they are not checked in the default implementation,
CPython CPython is the reference implementation of the Python programming language. Written in C and Python, CPython is the default and most widely used implementation of the Python language. CPython can be defined as both an interpreter and a compi ...
. An experimental optional static type-checker, ''mypy'', supports compile-time type checking.


Arithmetic operations

Python has the usual symbols for arithmetic operators (+, -, *, /), the floor division operator // and the
modulo operation In computing, the modulo operation returns the remainder or signed remainder of a division, after one number is divided by another (called the '' modulus'' of the operation). Given two positive numbers and , modulo (often abbreviated as ) is th ...
% (where the remainder can be negative, e.g. 4 % -3

-2
). It also has ** for
exponentiation Exponentiation is a mathematical operation, written as , involving two numbers, the '' base'' and the ''exponent'' or ''power'' , and pronounced as " (raised) to the (power of) ". When is a positive integer, exponentiation corresponds to re ...
, e.g. 5**3

125
and 9**0.5

3.0
, and a matrix‑multiplication operator @ . These operators work like in traditional math; with the same precedence rules, the operators infix (+ and - can also be unary to represent positive and negative numbers respectively). The division between integers produces floating-point results. The behavior of division has changed significantly over time: * Current Python (i.e. since 3.0) changed / to always be floating-point division, e.g. . * The floor division // operator was introduced. So 7//3

2
, -7//3

-3
, 7.5//3

2.0
and -7.5//3

-3.0
. Adding causes a module used in Python 2.7 to use Python 3.0 rules for division (see above). In Python terms, / is ''true division'' (or simply ''division''), and // is ''floor division.'' / before version 3.0 is ''classic division''. Rounding towards negative infinity, though different from most languages, adds consistency. For instance, it means that the equation is always true. It also means that the equation is valid for both positive and negative values of a. However, maintaining the validity of this equation means that while the result of a%b is, as expected, in the
half-open interval In mathematics, a (real) interval is a set of real numbers that contains all real numbers lying between any two numbers of the set. For example, the set of numbers satisfying is an interval which contains , , and all numbers in between. Othe ...
, ''b''), where b is a positive integer, it has to lie in the interval (''b'', 0when b is negative. Python provides a round function for
rounding Rounding means replacing a number with an approximate value that has a shorter, simpler, or more explicit representation. For example, replacing $ with $, the fraction 312/937 with 1/3, or the expression with . Rounding is often done to ob ...
a float to the nearest integer. For tie-breaking, Python 3 uses round to even: round(1.5) and round(2.5) both produce 2. Versions before 3 used round-away-from-zero: round(0.5) is 1.0, round(-0.5) is −1.0. Python allows boolean expressions with multiple equality relations in a manner that is consistent with general use in mathematics. For example, the expression a < b < c tests whether a is less than b and b is less than c. C-derived languages interpret this expression differently: in C, the expression would first evaluate a < b, resulting in 0 or 1, and that result would then be compared with c. Python uses
arbitrary-precision arithmetic In computer science, arbitrary-precision arithmetic, also called bignum arithmetic, multiple-precision arithmetic, or sometimes infinite-precision arithmetic, indicates that calculations are performed on numbers whose digits of precision are li ...
for all integer operations. The Decimal type/class in the decimal module provides decimal floating-point numbers to a pre-defined arbitrary precision and several rounding modes. The Fraction class in the fractions module provides arbitrary precision for
rational number In mathematics, a rational number is a number that can be expressed as the quotient or fraction of two integers, a numerator and a non-zero denominator . For example, is a rational number, as is every integer (e.g. ). The set of all ration ...
s. Due to Python's extensive mathematics library, and the third-party library NumPy that further extends the native capabilities, it is frequently used as a scientific scripting language to aid in problems such as numerical data processing and manipulation.


Programming examples

Hello world ''Hello'' is a salutation or greeting in the English language. It is first attested in writing from 1826. Early uses ''Hello'', with that spelling, was used in publications in the U.S. as early as the 18 October 1826 edition of the '' Norwich ...
program: print('Hello, world!') Program to calculate the factorial of a positive integer: n = int(input('Type a number, and its factorial will be printed: ')) if n < 0: raise ValueError('You must enter a non-negative integer') factorial = 1 for i in range(2, n + 1): factorial *= i print(factorial)


Libraries

Python's large standard library provides tools suited to many tasks and is commonly cited as one of its greatest strengths. For Internet-facing applications, many standard formats and protocols such as
MIME Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message ...
and
HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide We ...
are supported. It includes modules for creating
graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...
s, connecting to
relational database A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
s, generating pseudorandom numbers, arithmetic with arbitrary-precision decimals, manipulating
regular expression A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...
s, and
unit testing In computer programming, unit testing is a software testing method by which individual units of source code—sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures&md ...
. Some parts of the standard library are covered by specifications—for example, the
Web Server Gateway Interface The Web Server Gateway Interface (WSGI, pronounced ''whiskey'' or ) is a simple calling convention for web servers to forward requests to web applications or frameworks written in the Python programming language. The current version of WSGI, v ...
(WSGI) implementation wsgiref follows PEP 333—but most are specified by their code, internal documentation, and
test suite In software development, a test suite, less commonly known as a validation suite, is a collection of test cases that are intended to be used to test a software program to show that it has some specified set of behaviors. A test suite often contai ...
s. However, because most of the standard library is cross-platform Python code, only a few modules need altering or rewriting for variant implementations. the
Python Package Index The Python Package Index, abbreviated as PyPI () and also known as the Cheese Shop (a reference to the ''Monty Python's Flying Circus'' sketch " Cheese Shop"), is the official third-party software repository for Python. It is analogous to the C ...
(PyPI), the official repository for third-party Python software, contains over 415,000 packages with a wide range of functionality, including:


Development environments

Most Python implementations (including CPython) include a
read–eval–print loop A read–eval–print loop (REPL), also termed an interactive toplevel or language shell, is a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user; a program written ...
(REPL), permitting them to function as a
command line interpreter A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...
for which users enter statements sequentially and receive results immediately. Python also comes with an Integrated development environment (IDE) called
IDLE Idle generally refers to idleness, a lack of motion or energy. Idle or ''idling'', may also refer to: Technology * Idle (engine), engine running without load ** Idle speed * Idle (CPU), CPU non-utilisation or low-priority mode ** Synchronous ...
, which is more beginner-oriented. Other shells, including
IDLE Idle generally refers to idleness, a lack of motion or energy. Idle or ''idling'', may also refer to: Technology * Idle (engine), engine running without load ** Idle speed * Idle (CPU), CPU non-utilisation or low-priority mode ** Synchronous ...
and IPython, add further abilities such as improved auto-completion, session state retention, and
syntax highlighting Syntax highlighting is a feature of text editors that are used for programming, scripting, or markup languages, such as HTML. The feature displays text, especially source code, in different colours and fonts according to the category of terms ...
. As well as standard desktop
integrated development environment An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of at least a source code editor, build automation tools a ...
s, there are
Web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used o ...
-based IDEs, including
SageMath SageMath (previously Sage or SAGE, "System for Algebra and Geometry Experimentation") is a computer algebra system (CAS) with features covering many aspects of mathematics, including algebra, combinatorics, graph theory, numerical analysis, numbe ...
, for developing science- and math-related programs;
PythonAnywhere PythonAnywhere is an online integrated development environment (IDE) and web hosting service (Platform as a service) based on the Python programming language. Founded by Giles Thomas and Robert Smithson in 2012, it provides in-browser access to s ...
, a browser-based IDE and hosting environment; and Canopy IDE, a commercial IDE emphasizing
scientific computing Computational science, also known as scientific computing or scientific computation (SC), is a field in mathematics that uses advanced computing capabilities to understand and solve complex problems. It is an area of science that spans many disc ...
.


Implementations


Reference implementation

CPython CPython is the reference implementation of the Python programming language. Written in C and Python, CPython is the default and most widely used implementation of the Python language. CPython can be defined as both an interpreter and a compi ...
is the
reference implementation In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation o ...
of Python. It is written in C, meeting the C89 standard (Python 3.11 uses
C11 C11, C.XI, C-11 or C.11 may refer to: Transport * C-11 Fleetster, a 1920s American light transport aircraft for use of the United States Assistant Secretary of War * Fokker C.XI, a 1935 Dutch reconnaissance seaplane * LET C-11, a license-build var ...
) with several select
C99 C99 (previously known as C9X) is an informal name for ISO/IEC 9899:1999, a past version of the C programming language standard. It extends the previous version ( C90) with new features for the language and the standard library, and helps impl ...
features (With later C versions out, it is considered outdated. CPython includes its own C extensions, but third-party extensions are not limited to older C versions—e.g. they can be implemented with
C11 C11, C.XI, C-11 or C.11 may refer to: Transport * C-11 Fleetster, a 1920s American light transport aircraft for use of the United States Assistant Secretary of War * Fokker C.XI, a 1935 Dutch reconnaissance seaplane * LET C-11, a license-build var ...
or C++.) It compiles Python programs into an intermediate
bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (norma ...
which is then executed by its
virtual machine In computing, a virtual machine (VM) is the virtualization/emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardw ...
. CPython is distributed with a large standard library written in a mixture of C and native Python, and is available for many platforms, including Windows (starting with Python 3.9, the Python installer deliberately fails to install on
Windows 7 Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly ...
and 8;
Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Windows 2000 for high-end and ...
was supported until Python 3.5) and most modern
Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
systems, including macOS (and
Apple M1 Apple M1 is a series of ARM-based systems-on-a-chip (SoCs) designed by Apple Inc. as a central processing unit (CPU) and graphics processing unit (GPU) for its Mac desktops and notebooks, and the iPad Pro and iPad Air tablets. The M1 c ...
Macs, since Python 3.9.1, with experimental installer) and unofficial support for e.g. VMS. Platform portability was one of its earliest priorities. (During Python 1 and 2 development, even
OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...
and
Solaris Solaris may refer to: Arts and entertainment Literature, television and film * ''Solaris'' (novel), a 1961 science fiction novel by Stanisław Lem ** ''Solaris'' (1968 film), directed by Boris Nirenburg ** ''Solaris'' (1972 film), directed by ...
were supported, but support has since been dropped for many platforms.)


Other implementations

*
PyPy PyPy () is an implementation of the Python programming language. PyPy often runs faster than the standard implementation CPython because PyPy uses a just-in-time compiler. Most Python code runs well on PyPy except for code that depends on CPyth ...
is a fast, compliant interpreter of Python 2.7 and 3.8. Its
just-in-time compiler In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compilation during execution of a program (at run time) rather than before execution. This may cons ...
often brings a significant speed improvement over CPython but some libraries written in C cannot be used with it. *
Stackless Python Stackless Python, or Stackless, is a Python programming language interpreter, so named because it avoids depending on the C call stack for its own stack. In practice, Stackless Python uses the C stack, but the stack is cleared between function c ...
is a significant fork of CPython that implements
microthread Microthreads are functions that may run in parallel to gain increased performance in microprocessors. They provide an execution model that uses a few additional instructions in a conventional processor to break code down into fragments that execut ...
s; it does not use the
call stack In computer science, a call stack is a stack data structure that stores information about the active subroutines of a computer program. This kind of stack is also known as an execution stack, program stack, control stack, run-time stack, or ma ...
in the same way, thus allowing massively concurrent programs. PyPy also has a stackless version. *
MicroPython MicroPython is a software implementation of a programming language largely compatible with Python 3, written in C, that is optimized to run on a microcontroller. MicroPython consists of a Python compiler to bytecode and a runtime interpreter ...
and
CircuitPython CircuitPython is an open-source derivative of the MicroPython programming language targeted toward students and beginners. Development of CircuitPython is supported by Adafruit Industries. It is a software implementation of the Python 3 programm ...
are Python 3 variants optimized for microcontrollers, including
Lego Mindstorms EV3 LEGO Mindstorms EV3 is the third generation robotics kit in LEGO's Mindstorms line. It is the successor to the second generation LEGO Mindstorms NXT kit. The "EV" designation refers to the "evolution" of the Mindstorms product line. "3" refers t ...
. * Pyston is a variant of the Python runtime that uses just-in-time compilation to speed up the execution of Python programs. * Cinder is a performance-oriented fork of CPython 3.8 that contains a number of optimizations including bytecode inline caching, eager evaluation of coroutines, a method-at-a-time
JIT Jit (also known as jiti, jit-jive and the Harare beat) is a style of popular Zimbabwean dance music. It features a swift rhythm played on drums and accompanied by a guitar. Jit evolved out many diverse influences, including domestic chimurenga, ...
, and an experimental bytecode compiler.


Unsupported implementations

Other just-in-time Python compilers have been developed, but are now unsupported: * Google began a project named
Unladen Swallow CPython is the reference implementation of the Python programming language. Written in C and Python, CPython is the default and most widely used implementation of the Python language. CPython can be defined as both an interpreter and a compi ...
in 2009, with the aim of speeding up the Python interpreter fivefold by using the
LLVM LLVM is a set of compiler and toolchain technologies that can be used to develop a front end for any programming language and a back end for any instruction set architecture. LLVM is designed around a language-independent intermediate repre ...
, and of improving its multithreading ability to scale to thousands of cores, while ordinary implementations suffer from the
global interpreter lock A global interpreter lock (GIL) is a mechanism used in computer-language interpreters to synchronize the execution of threads so that only one native thread (per process) can execute at a time. An interpreter that uses GIL always allows exactly o ...
. *
Psyco Psyco is an unmaintained specializing just-in-time compiler for pre-2.7 Python originally developed by Armin Rigo and further maintained and developed by Christian Tismer. Development ceased in December, 2011. Psyco ran on BSD-derived opera ...
is a discontinued just-in-time specializing compiler that integrates with CPython and transforms bytecode to machine code at runtime. The emitted code is specialized for certain data types and is faster than the standard Python code. Psyco does not support Python 2.7 or later. * PyS60 was a Python 2 interpreter for
Series 60 The S60 Platform (formerly Series 60 User Interface) was a software platform for smartphones that runs on top of the Symbian operating system. It was created by Nokia based on the 'Pearl' user interface from Symbian Ltd. It was introduced at ...
mobile phones released by
Nokia Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational corporation, multinational telecommunications industry, telecommunications, technology company, information technology, and consumer electronics corporatio ...
in 2005. It implemented many of the modules from the standard library and some additional modules for integrating with the
Symbian Symbian is a discontinued mobile operating system A mobile operating system is an operating system for mobile phones, tablets, smartwatches, smartglasses, or other non-laptop personal mobile computing devices. While computers such as typic ...
operating system. The Nokia
N900 The Nokia N900 is a smartphone made by Nokia. It supersedes the Nokia N810. Its default operating system, Maemo 5, is a Linux-based OS originally developed for the Nokia 770 Internet Tablet. It is the first Nokia device based upon the Texas I ...
also supports Python with
GTK GTK (formerly GIMP ToolKit and GTK+) is a free and open-source cross-platform widget toolkit for creating graphical user interfaces (GUIs). It is licensed under the terms of the GNU Lesser General Public License, allowing both free and propriet ...
widget libraries, enabling programs to be written and run on the target device.


Cross-compilers to other languages

There are several compilers to high-level object languages, with either unrestricted Python, a restricted subset of Python, or a language similar to Python as the source language: * Brython, Transcrypt and
Pyjs Www.google.com (formerly Pyjamas before May 2012), is a rich web application framework for developing client-side web and desktop applications in Python (programming language), Python. The resulting applications can be run in a web browser or as ...
(latest release in 2012) compile Python to
JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...
. *
Cython Cython () is a programming language that aims to be a superset of the Python programming language, designed to give C-like performance with code that is written mostly in Python with optional additional C-inspired syntax. Cython is a compiled ...
compiles (a superset of) Python 2.7 to C (while the resulting code is also usable with Python 3 and also e.g. C++). * Nuitka compiles Python into C. *
Numba Numba is an open-source JIT compiler that translates a subset of Python and NumPy into fast machine code using LLVM, via the llvmlite Python package. It offers a range of options for parallelising Python code for CPUs and GPUs, often with only ...
uses LLVM to compile a subset of Python to machine code. * Pythran compiles a subset of Python 3 to C++ (
C++11 C++11 is a version of the ISO/ IEC 14882 standard for the C++ programming language. C++11 replaced the prior version of the C++ standard, called C++03, and was later replaced by C++14. The name follows the tradition of naming language versions b ...
). *
RPython PyPy () is an implementation of the Python programming language. PyPy often runs faster than the standard implementation CPython because PyPy uses a just-in-time compiler. Most Python code runs well on PyPy except for code that depends on CPyth ...
can be compiled to C, and is used to build the PyPy interpreter of Python. * The Python → 11l → C++ transpiler compiles a subset of Python 3 to C++ ( C++17). Specialized: *
MyHDL MyHDL is a Python (programming language), Python-based hardware description language (HDL). Features of MyHDL include: * The ability to generate VHDL and Verilog code from a MyHDL design. * The ability to generate a testbench (Conversion of test be ...
is a Python-based
hardware description language In computer engineering, a hardware description language (HDL) is a specialized computer language used to describe the structure and behavior of electronic circuits, and most commonly, digital logic circuits. A hardware description language en ...
(HDL), that converts MyHDL code to
Verilog Verilog, standardized as IEEE 1364, is a hardware description language (HDL) used to model electronic systems. It is most commonly used in the design and verification of digital circuits at the register-transfer level of abstraction. It is als ...
or
VHDL The VHSIC Hardware Description Language (VHDL) is a hardware description language (HDL) that can model the behavior and structure of digital systems at multiple levels of abstraction, ranging from the system level down to that of logic gate ...
code. Older projects (or not to be used with Python 3.x and latest syntax): * Google's Grumpy (latest release in 2017)
transpile A source-to-source translator, source-to-source compiler (S2S compiler), transcompiler, or transpiler is a type of translator that takes the source code of a program written in a programming language as its input and produces an equivalent sou ...
s Python 2 to Go. * IronPython allows running Python 2.7 programs (and an
alpha Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
, released in 2021, is also available for "Python 3.4, although features and behaviors from later versions may be included") on the .NET Common Language Runtime. * Jython compiles Python 2.7 to Java bytecode, allowing the use of the Java libraries from a Python program. *
Pyrex Pyrex (trademarked as ''PYREX'' and ''pyrex'') is a brand introduced by Corning Inc. in 1915 for a line of clear, low-thermal-expansion borosilicate glass used for laboratory glassware and kitchenware. It was later expanded to include kitchenwa ...
(latest release in 2010) and Shed Skin (latest release in 2013) compile to C and C++ respectively.


Performance

Performance comparison of various Python implementations on a non-numerical (combinatorial) workload was presented at EuroSciPy '13. Python's performance compared to other programming languages is also benchmarked by
The Computer Language Benchmarks Game The Computer Language Benchmarks Game (formerly called The Great Computer Language Shootout) is a free software project for comparing how a given subset of simple algorithms can be implemented in various popular programming languages. The project ...
.


Development

Python's development is conducted largely through the ''Python Enhancement Proposal'' (PEP) process, the primary mechanism for proposing major new features, collecting community input on issues, and documenting Python design decisions. Python coding style is covered in PEP 8. Outstanding PEPs are reviewed and commented on by the Python community and the steering council. Enhancement of the language corresponds with the development of the CPython reference implementation. The mailing list python-dev is the primary forum for the language's development. Specific issues were originally discussed in the Roundup
bug tracker A bug tracking system or defect tracking system is a software application that keeps track of reported software bugs in software development projects. It may be regarded as a type of issue tracking system. Many bug tracking systems, such as those ...
hosted at by the foundation. In 2022, all issues and discussions were migrated to
GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...
. Development originally took place on a self-hosted source-code repository running
Mercurial Mercurial is a distributed revision control tool for software developers. It is supported on Microsoft Windows and Unix-like systems, such as FreeBSD, macOS, and Linux. Mercurial's major design goals include high performance and scalability, d ...
, until Python moved to
GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...
in January 2017. CPython's public releases come in three types, distinguished by which part of the version number is incremented: * Backward-incompatible versions, where code is expected to break and needs to be manually
ported In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desi ...
. The first part of the version number is incremented. These releases happen infrequently—version 3.0 was released 8 years after 2.0. According to Guido van Rossum, a version 4.0 is very unlikely to ever happen. * Major or "feature" releases are largely compatible with the previous version but introduce new features. The second part of the version number is incremented. Starting with Python 3.9, these releases are expected to happen annually. Each major version is supported by bug fixes for several years after its release. * Bugfix releases, which introduce no new features, occur about every 3 months and are made when a sufficient number of bugs have been fixed upstream since the last release. Security vulnerabilities are also patched in these releases. The third and final part of the version number is incremented. Many alpha, beta, and release-candidates are also released as previews and for testing before final releases. Although there is a rough schedule for each release, they are often delayed if the code is not ready. Python's development team monitors the state of the code by running the large
unit test In computer programming, unit testing is a software testing method by which individual units of source code—sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures&md ...
suite during development. The major
academic conference An academic conference or scientific conference (also congress, symposium, workshop, or meeting) is an event for researchers (not necessarily academics) to present and discuss their scholarly work. Together with academic or scientific journal ...
on Python is
PyCon The Python Conference (also called PyCon) is the largestpage 10 annual convention for the discussion and promotion of the Python programming language. It originated in the United States but is also held in more than 40 other countries. It was one ...
. There are also special Python mentoring programs, such as
Pyladies PyLadies is an international mentorship group which focuses on helping more women become active participants in the Python open-source community. It is part of the Python Software Foundation. It was started in Los Angeles in 2011. The mission of ...
. Python 3.10 deprecated wstr (to be removed in Python 3.12; meaning Python extensions need to be modified by then), and added
pattern matching In computer science, pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually has to be exact: "either it will or will not be ...
to the language.


API documentation generators

Tools that can generate documentation for Python API include
pydoc Pydoc is the standard documentation module for the programming language Python. Similar to the functionality of Perldoc within Perl and Javadoc within Java, Pydoc allows Python programmers to access Python's documentation help files, generate text ...
(available as part of the standard library),
Sphinx A sphinx ( , grc, σφίγξ , Boeotian: , plural sphinxes or sphinges) is a mythical creature with the head of a human, the body of a lion, and the wings of a falcon. In Greek tradition, the sphinx has the head of a woman, the haunches of ...
,
Pdoc Pdoc is a software package for generating API documentation for Python programming language. Built as a successor to Epydoc, Pdoc uses introspection to extract documentation from source code docstrings and allows programmers to generate HTML d ...
and its forks,
Doxygen Doxygen ( ) is a documentation generator and static analysis tool for software source trees. When used as a documentation generator, Doxygen extracts information from specially-formatted comments within the code. When used for analysis, Doxyge ...
and
Graphviz Graphviz (short for ''Graph Visualization Software'') is a package of open-source tools initiated by AT&T Labs Research for drawing graphs specified in DOT language scripts having the file name extension "gv". It also provides libraries for ...
, among others.


Naming

Python's name is derived from the British comedy group Monty Python, whom Python creator Guido van Rossum enjoyed while developing the language. Monty Python references appear frequently in Python code and culture; for example, the
metasyntactic variable A metasyntactic variable is a specific word or set of words identified as a placeholder in computer science and specifically computer programming. These words are commonly found in source code and are intended to be modified or substituted before ...
s often used in Python literature are ''spam'' and ''eggs'' instead of the traditional ''foo'' and ''bar''. The official Python documentation also contains various references to Monty Python routines. The prefix ''Py-'' is used to show that something is related to Python. Examples of the use of this prefix in names of Python applications or libraries include
Pygame Pygame is a cross-platform set of Python modules designed for writing video games. It includes computer graphics and sound libraries designed to be used with the Python programming language. History Pygame was originally written by Pete Shinners ...
, a binding of SDL to Python (commonly used to create games);
PyQt PyQt is a Python binding of the cross-platform GUI toolkit Qt, implemented as a Python plug-in. PyQt is free software developed by the British firm Riverbank Computing. It is available under similar terms to Qt versions older than 4.5; this m ...
and
PyGTK PyGTK is a set of Python wrappers for the GTK graphical user interface library. PyGTK is free software and licensed under the LGPL. It is analogous to PyQt/ PySide and wxPython, the Python wrappers for Qt and wxWidgets, respectively. Its ...
, which bind Qt and GTK to Python respectively; and
PyPy PyPy () is an implementation of the Python programming language. PyPy often runs faster than the standard implementation CPython because PyPy uses a just-in-time compiler. Most Python code runs well on PyPy except for code that depends on CPyth ...
, a Python implementation originally written in Python.


Popularity

Since 2003, Python has consistently ranked in the top ten most popular programming languages in the
TIOBE Programming Community Index The TIOBE programming community index is a measure of popularity of programming languages, created and maintained by TIOBE Software BV, based in Eindhoven, the Netherlands. TIOBE stands for ''The Importance of Being Earnest'', the title of an 18 ...
where, , it is the most popular language (ahead of
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
, and C). It was selected Programming Language of the Year (for "the highest rise in ratings in a year") in 2007, 2010, 2018, and 2020 (the only language to do so four times). An empirical study found that scripting languages, such as Python, are more productive than conventional languages, such as C and Java, for programming problems involving string manipulation and search in a dictionary, and determined that memory consumption was often "better than Java and not much worse than C or C++". Large organizations that use Python include
Wikipedia Wikipedia is a multilingual free online encyclopedia written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and using a wiki-based editing system. Wikipedia is the largest and most-read refer ...
,
Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...
,
Yahoo! Yahoo! (, styled yahoo''!'' in its logo) is an American web services provider. It is headquartered in Sunnyvale, California and operated by the namesake company Yahoo Inc., which is 90% owned by investment funds managed by Apollo Global Man ...
,
CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...
,
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
,
Facebook Facebook is an online social media and social networking service owned by American company Meta Platforms. Founded in 2004 by Mark Zuckerberg with fellow Harvard College students and roommates Eduardo Saverin, Andrew McCollum, Dustin M ...
,
Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...
,
Instagram Instagram is a photo and video sharing social networking service owned by American company Meta Platforms. The app allows users to upload media that can be edited with filters and organized by hashtags and geographical tagging. Posts can ...
,
Spotify Spotify (; ) is a proprietary Swedish audio streaming and media services provider founded on 23 April 2006 by Daniel Ek and Martin Lorentzon. It is one of the largest music streaming service providers, with over 456 million monthly active us ...
, and some smaller entities like
ILM Ilm or ILM may refer to: Acronyms * Identity Lifecycle Manager, a Microsoft Server Product * '' I Love Money,'' a TV show on VH1 * Independent Loading Mechanism, a mounting system for CPU sockets * Industrial Light & Magic, an American motion ...
and ITA. The social news networking site
Reddit Reddit (; stylized in all lowercase as reddit) is an American social news aggregation, content rating, and discussion website. Registered users (commonly referred to as "Redditors") submit content to the site such as links, text posts, imag ...
was written mostly in Python.


Uses

Python can serve as a
scripting language A scripting language or script language is a programming language that is used to manipulate, customize, and automate the facilities of an existing system. Scripting languages are usually interpreted at runtime rather than compiled. A scripting ...
for
web application A web application (or web app) is application software that is accessed using a web browser. Web applications are delivered on the World Wide Web to users with an active network connection. History In earlier computing models like client-serv ...
s, e.g., via for the
Apache webserver The Apache HTTP Server ( ) is a free and open-source cross-platform web server software, released under the terms of Apache License 2.0. Apache is developed and maintained by an open community of developers under the auspices of the Apache S ...
. With
Web Server Gateway Interface The Web Server Gateway Interface (WSGI, pronounced ''whiskey'' or ) is a simple calling convention for web servers to forward requests to web applications or frameworks written in the Python programming language. The current version of WSGI, v ...
, a standard API has evolved to facilitate these applications.
Web framework A web framework (WF) or web application framework (WAF) is a software framework that is designed to support the development of web applications including web services, web resources, and web APIs. Web frameworks provide a standard way to build and ...
s like Django,
Pylons Pylon may refer to: Structures and boundaries * Pylon (architecture), the gateway to the inner part of an Ancient Egyptian temple or Christian cathedral * Pylon, a support tower structure for suspension bridges or highways * Pylon, an orange mar ...
,
Pyramid A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilat ...
,
TurboGears TurboGears is a Python web application framework consisting of several WSGI components such as WebOb, SQLAlchemyKajikitemplate language and Repoze. TurboGears is designed around the model–view–controller (MVC) architecture, much like Stru ...
,
web2py Web2py is an open-source web application framework written in the Python programming language. Web2py allows web developers to program dynamic web content using Python. Web2py is designed to help reduce tedious web development tasks, such a ...
,
Tornado A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, altho ...
,
Flask Flask may refer to: Container * Hip flask, a small container used to carry a small amount of liquid * Laboratory flask, laboratory glassware for holding larger volumes than simple test tubes ** Erlenmeyer flask, a common laboratory flask wit ...
, Bottle, and
Zope Zope is a family of free and open-source web application servers written in Python, and their associated online community. Zope stands for "Z Object Publishing Environment", and was the first system using the now common object publishing methodol ...
support developers in the design and maintenance of complex applications. Pyjs and IronPython can be used to develop the client-side of Ajax-based applications.
SQLAlchemy SQLAlchemy is an open-source SQL toolkit and object-relational mapper (ORM) for the Python programming language released under the MIT License. Description SQLAlchemy's philosophy is that relational databases behave less like object collectio ...
can be used as a data mapper to a relational database. Twisted is a framework to program communications between computers, and is used (for example) by
Dropbox Dropbox is a file hosting service operated by the American company Dropbox, Inc., headquartered in San Francisco, California, U.S. that offers cloud storage, file synchronization, personal cloud, and client software. Dropbox was founded in 2007 ...
. Libraries such as NumPy,
SciPy SciPy (pronounced "sigh pie") is a free and open-source Python library used for scientific computing and technical computing. SciPy contains modules for optimization, linear algebra, integration, interpolation, special functions, FFT, ...
, and Matplotlib allow the effective use of Python in scientific computing, with specialized libraries such as Biopython and Astropy providing domain-specific functionality.
SageMath SageMath (previously Sage or SAGE, "System for Algebra and Geometry Experimentation") is a computer algebra system (CAS) with features covering many aspects of mathematics, including algebra, combinatorics, graph theory, numerical analysis, numbe ...
is a
computer algebra system A computer algebra system (CAS) or symbolic algebra system (SAS) is any mathematical software with the ability to manipulate mathematical expressions in a way similar to the traditional manual computations of mathematicians and scientists. The d ...
with a
notebook interface A notebook interface (also called a computational notebook) is a virtual notebook environment used for literate programming, a method of writing computer programs. Some notebooks are WYSIWYG environments including executable calculations embedded i ...
programmable in Python: its library covers many aspects of
mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
, including
algebra Algebra () is one of the broad areas of mathematics. Roughly speaking, algebra is the study of mathematical symbols and the rules for manipulating these symbols in formulas; it is a unifying thread of almost all of mathematics. Elementary a ...
, combinatorics,
numerical mathematics Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods ...
,
number theory Number theory (or arithmetic or higher arithmetic in older usage) is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic function, integer-valued functions. German mathematician Carl Friedrich Gauss (1777� ...
, and
calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...
.
OpenCV OpenCV (''Open Source Computer Vision Library'') is a library of programming functions mainly aimed at real-time computer vision. Originally developed by Intel, it was later supported by Willow Garage then Itseez (which was later acquired by In ...
has Python bindings with a rich set of features for computer vision and
image processing An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...
. Python is commonly used in
artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech re ...
projects and machine learning projects with the help of libraries like
TensorFlow TensorFlow is a free and open-source software library for machine learning and artificial intelligence. It can be used across a range of tasks but has a particular focus on training and inference of deep neural networks. "It is machine learnin ...
,
Keras Keras is an open-source software library that provides a Python interface for artificial neural networks. Keras acts as an interface for the TensorFlow library. Up until version 2.3, Keras supported multiple backends, including TensorFlow, Mic ...
,
Pytorch PyTorch is a machine learning framework based on the Torch library, used for applications such as computer vision and natural language processing, originally developed by Meta AI and now part of the Linux Foundation umbrella. It is free and open ...
, and
scikit-learn scikit-learn (formerly scikits.learn and also known as sklearn) is a free software machine learning library for the Python programming language. It features various classification, regression and clustering algorithms including support-vector ...
. As a scripting language with a modular architecture, simple syntax, and rich text processing tools, Python is often used for
natural language processing Natural language processing (NLP) is an interdisciplinary subfield of linguistics, computer science, and artificial intelligence concerned with the interactions between computers and human language, in particular how to program computers to pro ...
. Python can also be used to create games, with libraries such as
Pygame Pygame is a cross-platform set of Python modules designed for writing video games. It includes computer graphics and sound libraries designed to be used with the Python programming language. History Pygame was originally written by Pete Shinners ...
, which can make 2D games. Python has been successfully embedded in many software products as a scripting language, including in
finite element method The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat ...
software such as
Abaqus Abaqus FEA (formerly ABAQUS) is a software suite for finite element analysis and computer-aided engineering, originally released in 1978. The name and logo of this software are based on the abacus calculation tool. The Abaqus product suite consis ...
, 3D parametric modelers like
FreeCAD FreeCAD is a general-purpose parametric 3D computer-aided design (CAD) modeler and a building information modeling (BIM) software application with finite element method (FEM) support. It is intended for mechanical engineering product design bu ...
, 3D animation packages such as 3ds Max,
Blender A blender (sometimes called a mixer or liquidiser in British English) is a kitchen and laboratory appliance used to mix, crush, purée or emulsify food and other substances. A stationary blender consists of a blender container with a rotating me ...
,
Cinema 4D Cinema 4D is a 3D software suite developed by the German company Maxon. Overview As of R21, only one version of Cinema 4D is available. It replaces all previous variants, including BodyPaint 3D, and includes all features of the past 'Studio' ...
,
Lightwave LightWave 3D is a 3D computer graphics program developed by NewTek. It has been used in films, television, motion graphics, digital matte painting, visual effects, video game development, product design, architectural visualizations, virtu ...
,
Houdini Harry Houdini (, born Erik Weisz; March 24, 1874 – October 31, 1926) was a Hungarian-American escape artist, magic man, and stunt performer, noted for his escape acts. His pseudonym is a reference to his spiritual master, French magician R ...
,
Maya Maya may refer to: Civilizations * Maya peoples, of southern Mexico and northern Central America ** Maya civilization, the historical civilization of the Maya peoples ** Maya language, the languages of the Maya peoples * Maya (Ethiopia), a popul ...
, modo, MotionBuilder,
Softimage Autodesk Softimage, or simply Softimage () was a 3D computer graphics application, for producing 3D computer graphics, 3D modeling, and computer animation. Now owned by Autodesk and formerly titled Softimage, XSI, the software has been predomi ...
, the visual effects compositor Nuke, 2D imaging programs like GIMP,
Inkscape Inkscape is a free and open-source vector graphics editor used to create vector images, primarily in Scalable Vector Graphics (SVG) format. Other formats can be imported and exported. Inkscape can render primitive vector shapes (e.g. rec ...
,
Scribus Scribus () is free and open-source desktop publishing (DTP) software available for most desktop operating systems. It is designed for layout, typesetting, and preparation of files for professional-quality image-setting equipment. Scribus can a ...
and
Paint Shop Pro PaintShop Pro (PSP) is a raster graphics editor, raster and vector graphics editor for Microsoft Windows. It was originally published by Jasc Software. In October 2004, Corel purchased Jasc Software and the distribution rights to Paint Shop Pro. P ...
, and musical notation programs like
scorewriter A scorewriter, or music notation program is software for creating, editing and printing sheet music. A scorewriter is to music notation what a word processor is to text, in that they typically provide flexible editing and automatic layout, and p ...
and
capella Capella is the brightest star in the northern constellation of Auriga. It has the Bayer designation α Aurigae, which is Latinised to Alpha Aurigae and abbreviated Alpha Aur or α Aur. Capella is the sixth-brightest star i ...
.
GNU Debugger The GNU Debugger (GDB) is a portable debugger that runs on many Unix-like systems and works for many programming languages, including Ada, C, C++, Objective-C, Free Pascal, Fortran, Go, and partially others. History GDB was first written ...
uses Python as a pretty printer to show complex structures such as C++ containers.
Esri Esri (; Environmental Systems Research Institute) is an American multinational geographic information system (GIS) software company. It is best known for its ArcGIS products. With a 43% market share, Esri is the world's leading supplier of GIS ...
promotes Python as the best choice for writing scripts in
ArcGIS ArcGIS is a family of client, server and online geographic information system (GIS) software developed and maintained by Esri. ArcGIS was first released in 1999 and originally was released as ARC/INFO, a command line based GIS system for manipul ...
. It has also been used in several video games, and has been adopted as first of the three available
programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming ...
s in
Google App Engine Google App Engine (often referred to as GAE or simply App Engine) is a cloud computing platform as a service for developing and hosting web applications in Google-managed data centers. Applications are sandboxed and run across multiple server ...
, the other two being
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
and Go. Many operating systems include Python as a standard component. It ships with most Linux distributions,
AmigaOS 4 AmigaOS 4 (abbreviated as OS4 or AOS4) is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code developed by Commodore, and partially on version 3.9 developed by Haage & Partne ...
(using Python 2.7),
FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...
(as a package), NetBSD, and OpenBSD (as a package) and can be used from the command line (terminal). Many Linux distributions use installers written in Python:
Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: '' Desktop'', ''Server'', and ''Core'' for Internet of things devices and robots. All ...
uses the
Ubiquity Ubiquity is a synonym for omnipresence, the property of being present everywhere. Ubiquity may also refer to: * Ubiquity (software), a simple graphical installer made for the Ubuntu operating system * Ubiquity (Firefox), an experimental extensi ...
installer, while
Red Hat Linux Red Hat Linux was a widely used commercial open-source Linux distribution created by Red Hat until its discontinuation in 2004. Early releases of Red Hat Linux were called Red Hat Commercial Linux. Red Hat published the first non-beta rele ...
and
Fedora Linux Fedora Linux is a Linux distribution developed by the Fedora Project. Fedora contains software distributed under various free and open-source licenses and aims to be on the leading edge of open-source technologies. Fedora is the upstream source ...
use the
Anaconda Anacondas or water boas are a group of large snakes of the genus '' Eunectes''. They are found in tropical South America. Four species are currently recognized. Description Although the name applies to a group of snakes, it is often used ...
installer. Gentoo Linux uses Python in its
package management system A package manager or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals w ...
,
Portage Portage or portaging (Canada: ; ) is the practice of carrying water craft or cargo over land, either around an obstacle in a river, or between two bodies of water. A path where items are regularly carried between bodies of water is also called a ...
. Python is used extensively in the
information security Information security, sometimes shortened to InfoSec, is the practice of protecting information by mitigating information risks. It is part of information risk management. It typically involves preventing or reducing the probability of unauthorize ...
industry, including in exploit development. Most of the
Sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...
software for the One Laptop per Child XO, developed at
Sugar Labs Sugar Labs is a community-run software project whose mission is to produce, distribute, and support the use of Sugar, an open source desktop environment and learning platform. Sugar Labs was initially established as a member project of the Softwa ...
since 2008, is written in Python. The
Raspberry Pi Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic ...
single-board computer project has adopted Python as its main user-programming language.
LibreOffice LibreOffice () is a free and open-source office productivity software suite, a project of The Document Foundation (TDF). It was forked in 2010 from OpenOffice.org, an open-sourced version of the earlier StarOffice. The LibreOffice suite co ...
includes Python and intends to replace Java with Python. Its Python Scripting Provider is a core feature since Version 4.0 from 7 February 2013.


Languages influenced by Python

Python's design and philosophy have influenced many other programming languages: * Boo uses indentation, a similar syntax, and a similar object model. * Cobra uses indentation and a similar syntax, and its ''Acknowledgements'' document lists Python first among languages that influenced it. *
CoffeeScript CoffeeScript is a programming language that compiles to JavaScript. It adds syntactic sugar inspired by Ruby, Python, and Haskell in an effort to enhance JavaScript's brevity and readability. Specific additional features include list comprehe ...
, a programming language that cross-compiles to JavaScript, has Python-inspired syntax. *
ECMAScript ECMAScript (; ES) is a JavaScript standard intended to ensure the interoperability of web pages across different browsers. It is standardized by Ecma International in the documenECMA-262 ECMAScript is commonly used for client-side scripting o ...
/
JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...
borrowed iterators and generators from Python. *
GDScript Godot ( /ˈɡɒdoʊ/) is a cross-platform, free and open-source game engine released under the MIT license. It was initially developed by Argentine software developers Juan Linietsky and Ariel Manzur for several companies in Latin America prior ...
, a scripting language very similar to Python, built-in to the Godot game engine. * Go is designed for the "speed of working in a dynamic language like Python" and shares the same syntax for slicing arrays. *
Groovy ''Groovy'' (or, less commonly, ''groovie'' or ''groovey'') is a slang colloquialism popular during the 1950s, '60s and '70s. It is roughly synonymous with words such as "excellent", "fashionable", or "amazing", depending on context. History The ...
was motivated by the desire to bring the Python design philosophy to
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
. *
Julia Julia is usually a feminine given name. It is a Latinate feminine form of the name Julio and Julius. (For further details on etymology, see the Wiktionary entry "Julius".) The given name ''Julia'' had been in use throughout Late Antiquity (e.g ...
was designed to be "as usable for general programming as Python". * Nim uses indentation and similar syntax. *
Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called ...
's creator,
Yukihiro Matsumoto , also known as Matz, is a Japanese computer scientist and software programmer best known as the chief designer of the Ruby programming language and its original reference implementation, Matz's Ruby Interpreter (MRI). His demeanor has brough ...
, has said: "I wanted a scripting language that was more powerful than Perl, and more object-oriented than Python. That's why I decided to design my own language." *
Swift Swift or SWIFT most commonly refers to: * SWIFT, an international organization facilitating transactions between banks ** SWIFT code * Swift (programming language) * Swift (bird), a family of birds It may also refer to: Organizations * SWIFT, ...
, a programming language developed by Apple, has some Python-inspired syntax. Python's development practices have also been emulated by other languages. For example, the practice of requiring a document describing the rationale for, and issues surrounding, a change to the language (in Python, a PEP) is also used in
Tcl TCL or Tcl or TCLs may refer to: Business * TCL Technology, a Chinese consumer electronics and appliance company **TCL Electronics, a subsidiary of TCL Technology * Texas Collegiate League, a collegiate baseball league * Trade Centre Limited ...
, Erlang, and Swift.


See also

*
Python syntax and semantics The syntax of the Python programming language is the set of rules that defines how a Python program will be written and interpreted (by both the runtime system and by human readers). The Python language has many similarities to Perl, C, and J ...
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pip (package manager) Pip is a package-management system written in Python and is used to install and manage software packages. The Python Software Foundation recommends using pip for installing Python applications and its dependencies during deployment. Pip c ...
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List of programming languages This is an index to notable programming languages, in current or historical use. Dialects of BASIC, esoteric programming languages, and markup languages are not included. A programming language does not need to be imperative or Turing-complet ...
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History of programming languages The history of programming languages spans from documentation of early mechanical computers to modern tools for software development. Early programming languages were highly specialized, relying on mathematical notation and similarly obscure ...
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Comparison of programming languages Programming languages are used for controlling the behavior of a machine (often a computer). Like natural languages, programming languages follow the rules for syntax and semantics. There are thousands of programming languages and new ones are c ...


References


Sources

* * * *


Further reading

* * * * * * * Ramalho, Luciano (May 2022).
Fluent Python
' (2nd ed.). O'Reilly Media.
ISBN The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency. An ISBN is assigned to each separate edition an ...
978-1-4920-5632-4.


External links

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