This module provides direct access to all `built-in' identifiers of
Python; for example, __builtin__.open is the full name for the
built-in function open(). See chapter 2,
``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 open() function that wraps the built-in open(), this module can be used directly:
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() # ...
As an implementation detail, most modules have the name
__builtins__ (note the "s") made available as part of
their globals. The value of __builtins__ is normally either
this module or the value of this modules's __dict__
attribute. Since this is an implementation detail, it may not be used
by alternate implementations of Python.