cpython/Doc/lib/libintro.tex

\chapter{Introduction}

The Python library consists of three parts, with different levels of
integration with the interpreter.
Closest to the interpreter are built-in types, exceptions and functions.
Next are built-in modules, which are written in \C{} and linked statically
with the interpreter.
Finally there are standard modules that are implemented entirely in
Python, but are always available.
For efficiency, some standard modules may become built-in modules in
future versions of the interpreter.
\indexii{built-in}{types}
\indexii{built-in}{exceptions}
\indexii{built-in}{functions}
\indexii{built-in}{modules}
\indexii{standard}{modules}
\indexii{\C{}}{language}