Python is an extensible, interpreted, object-oriented programminglanguage. It supports a wide range of applications, from simple textprocessing scripts to interactive Web browsers.

While thePython Reference Manualdescribes the exact syntax and semantics of the language, it does notdescribe the standard library that is distributed with the language,and which greatly enhances its immediate usability. This librarycontains built-in modules (written in C) that provide access to systemfunctionality such as file I/O that would otherwise be inaccessible toPython programmers, as well as modules written in Python that providestandardized solutions for many problems that occur in everydayprogramming. Some of these modules are explicitly designed toencourage and enhance the portability of Python programs.

This library reference manual documents Python's standard library, aswell as many optional library modules (which may or may not beavailable, depending on whether the underlying platform supports themand on the configuration choices made at compile time). It alsodocuments the standard types of the language and its built-infunctions and exceptions, many of which are not or incompletelydocumented in the Reference Manual.

This manual assumes basic knowledge about the Python language. For aninformal introduction to Python, see thePython Tutorial; thePython Reference Manual remains thehighest authority on syntactic and semantic questions. Finally, themanual entitledExtending and Embeddingthe Python Interpreter describes how to add new extensions to Pythonand how to embed it in other applications.