:mod:`__builtin__` --- Built-in objects ======================================= .. module:: __builtin__ :synopsis: The module that provides the built-in namespace. 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 :func:`open`. See chapter :ref:`builtin`. 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 :func:`open` function that wraps the built-in :func:`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 :attr:`__dict__` attribute. Since this is an implementation detail, it may not be used by alternate implementations of Python.