| .. _library-index: | 
 |  | 
 | ############################### | 
 |   The Python Standard Library | 
 | ############################### | 
 |  | 
 | While :ref:`reference-index` 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 <https://pypi.org>`_. | 
 |  | 
 | .. We don't use :numbered: option for the TOC below as it enforces | 
 |    numbered sections for the entire stdlib docs.  If desired, | 
 |    :numbered: can be enabled on a per-module basis. | 
 | .. toctree:: | 
 |    :maxdepth: 2 | 
 |  | 
 |    intro.rst | 
 |    functions.rst | 
 |    constants.rst | 
 |    stdtypes.rst | 
 |    exceptions.rst | 
 |  | 
 |    text.rst | 
 |    binary.rst | 
 |    datatypes.rst | 
 |    numeric.rst | 
 |    functional.rst | 
 |    filesys.rst | 
 |    persistence.rst | 
 |    archiving.rst | 
 |    fileformats.rst | 
 |    crypto.rst | 
 |    allos.rst | 
 |    concurrency.rst | 
 |    ipc.rst | 
 |    netdata.rst | 
 |    markup.rst | 
 |    internet.rst | 
 |    mm.rst | 
 |    i18n.rst | 
 |    frameworks.rst | 
 |    tk.rst | 
 |    development.rst | 
 |    debug.rst | 
 |    distribution.rst | 
 |    python.rst | 
 |    custominterp.rst | 
 |    modules.rst | 
 |    language.rst | 
 |    windows.rst | 
 |    unix.rst | 
 |    superseded.rst | 
 |    undoc.rst | 
 |    security_warnings.rst |