: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.