the python standard library
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 also describes some of the optional components that are
commonly included in Python distributions.
Python’s standard library is very extensive, offering a wide
range of facilities as indicated by the long table of contents
listed below. The library contains built-in modules (written in C)
that provide access to system functionality such as file I/O that
would otherwise be inaccessible to Python programmers, as well
as modules written in Python that provide standardized solutions
for many problems that occur in everyday programming. Some of
these modules are explicitly designed to encourage and enhance
the portability of Python programs by abstracting away platform-specifics
into platform-neutral APIs.
The Python installers for the Windows platform usually include the entire
standard library and often also include many additional components. For
Unix-like operating systems Python is normally provided as a collection of
packages, so it may be necessary to use the packaging tools provided with
the operating system to obtain some or all of the optional components.
In addition to the standard library, there is a growing collection of several
thousand components (from individual programs and modules to packages
and entire application development frameworks), available from the Python Package Index.