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 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:
- 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.