
``__builtin__`` --- Built-in objects
************************************

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:

   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.
