In Python, all exceptions must be instances of a class that derives from BaseException. In a try statement with an except clause that mentions a particular class, that clause also handles any excep...| Python documentation
The functions and macros in this section are used for managing reference counts of Python objects.| Python documentation
Source code: Lib/operator.py The operator module exports a set of efficient functions corresponding to the intrinsic operators of Python. For example, operator.add(x, y) is equivalent to the expres...| Python documentation
This module provides an interface to the optional garbage collector. It provides the ability to disable the collector, tune the collection frequency, and set debugging options. It also provides acc...| Python documentation
This PEP outlines Python’s backwards compatibility policy.| Python Enhancement Proposals (PEPs)
Build Requirements: Features and minimum versions required to build CPython: A C11 compiler. Optional C11 features are not required., On Windows, Microsoft Visual Studio 2017 or later is required.,...| Python documentation
Source code: Lib/numbers.py The numbers module ( PEP 3141) defines a hierarchy of numeric abstract base classes which progressively define more operations. None of the types defined in this module ...| Python documentation
Source code: Lib/importlib/__init__.py Introduction: The purpose of the importlib package is three-fold. One is to provide the implementation of the import statement (and thus, by extension, the__i...| Python documentation
asyncio — Asynchronous I/O¶| docs.python.org
Source code: Lib/dis.py The dis module supports the analysis of CPython bytecode by disassembling it. The CPython bytecode which this module takes as an input is defined in the file Include/opcode....| Python documentation
This module provides APIs to manage, store, and access context-local state. The ContextVar class is used to declare and work with Context Variables. The copy_context() function and the Context clas...| Python documentation
Python can be initialized with Py_InitializeFromConfig() and the PyConfig structure. It can be preinitialized with Py_PreInitialize() and the PyPreConfig structure. There are two kinds of configura...| Python documentation
Source code: Lib/random.py This module implements pseudo-random number generators for various distributions. For integers, there is uniform selection from a range. For sequences, there is uniform s...| Python documentation
Currently the CPython runtime maintains a small amount of mutable state in the allocated memory of each object. Because of this, otherwise immutable objects are actually mutable. This can have a large negative impact on CPU and memory performance, esp...| Python Enhancement Proposals (PEPs)
Python Enhancement Proposals (PEPs)| Python Enhancement Proposals (PEPs)
This PEP lays out the theory referenced by PEP 484.| Python Enhancement Proposals (PEPs)
Source code: Lib/inspect.py The inspect module provides several useful functions to help get information about live objects such as modules, classes, methods, functions, tracebacks, frame objects, ...| Python documentation
Source code: Lib/io.py Overview: The io module provides Python’s main facilities for dealing with various types of I/O. There are three main types of I/O: text I/O, binary I/O and raw I/O. These ar...| Python documentation
This PEP proposes a new mechanism in the functools standard library module that provides a simple form of generic programming known as single-dispatch generic functions.| Python Enhancement Proposals (PEPs)
Python supports multiple ways to format text strings. These include %-formatting 1, str.format() 2, and string.Template 3. Each of these methods have their advantages, but in addition have disadvantages that make them cumbersome to use in practice. This...| Python Enhancement Proposals (PEPs)
Source code: Lib/_collections_abc.py This module provides abstract base classes that can be used to test whether a class provides a particular interface; for example, whether it is hashable or whet...| Python documentation
Structure of a program: A Python program is constructed from code blocks. A block is a piece of Python program text that is executed as a unit. The following are blocks: a module, a function body, ...| Python documentation
PEP 484 introduced type hints, a.k.a. type annotations. While its main focus was function annotations, it also introduced the notion of type comments to annotate variables:| Python Enhancement Proposals (PEPs)
The CPython interpreter scans the command line and the environment for various settings. CPython implementation detail: Other implementations’ command line schemes may differ. See Alternate Impleme...| Python documentation
The growth of Internet and general connectivity has triggered the proportionate need for responsive and scalable code. This proposal aims to answer that need by making writing explicitly asynchronous, concurrent Python code easier and more Pythonic.| Python Enhancement Proposals (PEPs)
Source code: Lib/codecs.py This module defines base classes for standard Python codecs (encoders and decoders) and provides access to the internal Python codec registry, which manages the codec and...| Python documentation
A small number of constants live in the built-in namespace. They are: Constants added by the site module: The site module (which is imported automatically during startup, except if the-S command-li...| Python documentation
Python code in one module gains access to the code in another module by the process of importing it. The import statement is the most common way of invoking the import machinery, but it is not the ...| Python documentation
This module provides access to some variables used or maintained by the interpreter and to functions that interact strongly with the interpreter. It is always available. Unless explicitly noted oth...| Python documentation
Source code: Lib/abc.py This module provides the infrastructure for defining abstract base classes(ABCs) in Python, as outlined in PEP 3119; see the PEP for why this was added to Python. (See also ...| Python documentation
PEP 492 introduced support for native coroutines and async/await syntax to Python 3.5. It is proposed here to extend Python’s asynchronous capabilities by adding support for asynchronous generators.| Python Enhancement Proposals (PEPs)
Certain objects available in Python wrap access to an underlying memory array or buffer. Such objects include the built-in bytes and bytearray, and some extension types like array.array. Third-part...| Python documentation
The following sections describe the standard types that are built into the interpreter. The principal built-in types are numerics, sequences, mappings, classes, instances and exceptions. Some colle...| Python documentation
Namespace packages are a mechanism for splitting a single Python package across multiple directories on disk. In current Python versions, an algorithm to compute the packages __path__ must be formulated. With the enhancement proposed here, the import ...| Python Enhancement Proposals (PEPs)
Source code: Lib/typing.py This module provides runtime support for type hints. Consider the function below: The function surface_area_of_cube takes an argument expected to be an instance of float,...| Python documentation
Source code: Lib/heapq.py This module provides an implementation of the heap queue algorithm, also known as the priority queue algorithm. Heaps are binary trees for which every parent node has a va...| Python documentation
Source code: Lib/collections/__init__.py This module implements specialized container datatypes providing alternatives to Python’s general purpose built-in containers, dict, list, set, and tuple.,,...| Python documentation
While The Python Language Reference describes the exact syntax and semantics of the Python language, this library reference manual describes the standard library that is distributed with Python. It...| Python documentation
This chapter explains the meaning of the elements of expressions in Python. Syntax Notes: In this and the following chapters, extended BNF notation will be used to describe syntax, not lexical anal...| Python documentation
Author, Raymond Hettinger,, Contact,,. Contents: Descriptor Guide- Primer- Simple example: A descriptor that returns a constant, Dynamic lookups, Managed attributes, Customiz...| Python documentation
This PEP proposes to add a new set of import hooks that offer better customization of the Python import mechanism. Contrary to the current __import__ hook, a new-style hook can be injected into the existing scheme, allowing for a finer grained control ...| Python Enhancement Proposals (PEPs)
Author, Andrew Dalke and Raymond Hettinger,. Python lists have a built-in list.sort() method that modifies the list in-place. There is also a sorted() built-in function that builds a new sorted lis...| Python documentation
Compound statements contain (groups of) other statements; they affect or control the execution of those other statements in some way. In general, compound statements span multiple lines, although i...| Python documentation
This module provides various time-related functions. For related functionality, see also the datetime and calendar modules. Although this module is always available, not all functions are available...| Python documentation
This module implements a number of iterator building blocks inspired by constructs from APL, Haskell, and SML. Each has been recast in a form suitable for Python. The module standardizes a core set...| Python documentation
A simple statement is comprised within a single logical line. Several simple statements may occur on a single line separated by semicolons. The syntax for simple statements is: Expression statement...| Python documentation
Source code: Lib/os.py This module provides a portable way of using operating system dependent functionality. If you just want to read or write a file see open(), if you want to manipulate paths, s...| Python documentation
PEP 3107 introduced syntax for function annotations, but the semantics were deliberately left undefined. There has now been enough 3rd party usage for static type analysis that the community would benefit from a standard vocabulary and baseline tools w...| Python Enhancement Proposals (PEPs)
CPython’s global interpreter lock (“GIL”) prevents multiple threads from executing Python code at the same time. The GIL is an obstacle to using multi-core CPUs from Python efficiently. This PEP proposes adding a build configuration (--disable-gil) to...| Python Enhancement Proposals (PEPs)
This module provides access to the mathematical functions defined by the C standard. These functions cannot be used with complex numbers; use the functions of the same name from the cmath module if...| Python documentation
Source code: Lib/functools.py The functools module is for higher-order functions: functions that act on or return other functions. In general, any callable object can be treated as a function for t...| Python documentation
Python Enhancement Proposals (PEPs)| Python Enhancement Proposals (PEPs)
Source code: Lib/venv/ The venv module supports creating lightweight “virtual environments”, each with their own independent set of Python packages installed in their site directories. A virtual en...| Python documentation
Objects, values and types: Objects are Python’s abstraction for data. All data in a Python program is represented by objects or by relations between objects. (In a sense, and in conformance to Von ...| Python documentation
