A small number of constants live in the built-in namespace.  They are:
- False
- 
  The false value of the bool type.
  
New in version 2.3.
- True
- 
  The true value of the bool type.
  
New in version 2.3.
- None
- 
  The sole value of types.NoneType.Noneis
  frequently used to represent the absence of a value, as when default
  arguments are not passed to a function.
- NotImplemented
- 
  Special value which can be returned by the ``rich comparison''
  special methods (__eq__(), __lt__(), and friends),
  to indicate that the comparison is not implemented with respect to
  the other type.
- Ellipsis
- 
  Special value used in conjunction with extended slicing syntax.
  
Release 2.4.3, documentation updated on 29 March 2006.
 
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