builtins — Built-in objects — Python v3.0.1 documentation (original) (raw)

This module provides direct access to all ‘built-in’ identifiers of Python; for example, builtins.open is the full name for the built-in functionopen(). 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-inopen(), this module can be used directly:

import builtins

def open(path): f = builtins.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.