ref: 2fe3b28f86ed4aa291fb8a620b948abe9c6a1f84
dir: /sys/src/cmd/python/Doc/lib/libbltin.tex/
\section{\module{__builtin__} ---
Built-in objects}
\declaremodule[builtin]{builtin}{__builtin__}
\modulesynopsis{The module that provides the built-in namespace.}
This module provides direct access to all `built-in' identifiers of
Python; for example, \code{__builtin__.open} is the full name for the
built-in function \function{open()}. See chapter~\ref{builtin},
``Built-in Objects.''
This module is not normally accessed explicitly by most applications,
but can be useful in modules that provide objects with the same name
as a built-in value, but in which the built-in of that name is also
needed. For example, in a module that wants to implement an
\function{open()} function that wraps the built-in \function{open()},
this module can be used directly:
\begin{verbatim}
import __builtin__
def open(path):
f = __builtin__.open(path, 'r')
return UpperCaser(f)
class UpperCaser:
'''Wrapper around a file that converts output to upper-case.'''
def __init__(self, f):
self._f = f
def read(self, count=-1):
return self._f.read(count).upper()
# ...
\end{verbatim}
As an implementation detail, most modules have the name
\code{__builtins__} (note the \character{s}) made available as part of
their globals. The value of \code{__builtins__} is normally either
this module or the value of this modules's \member{__dict__}
attribute. Since this is an implementation detail, it may not be used
by alternate implementations of Python.