41 lines
951 B
ReStructuredText
41 lines
951 B
ReStructuredText
|
|
Built-in Constants
|
|
==================
|
|
|
|
A small number of constants live in the built-in namespace. They are:
|
|
|
|
|
|
.. XXX False, True, None are keywords too
|
|
|
|
.. data:: False
|
|
|
|
The false value of the :class:`bool` type.
|
|
|
|
|
|
.. data:: True
|
|
|
|
The true value of the :class:`bool` type.
|
|
|
|
|
|
.. data:: None
|
|
|
|
The sole value of :attr:`types.NoneType`. ``None`` is frequently used to
|
|
represent the absence of a value, as when default arguments are not passed to a
|
|
function.
|
|
|
|
|
|
.. data:: NotImplemented
|
|
|
|
Special value which can be returned by the "rich comparison" special methods
|
|
(:meth:`__eq__`, :meth:`__lt__`, and friends), to indicate that the comparison
|
|
is not implemented with respect to the other type.
|
|
|
|
|
|
.. data:: Ellipsis
|
|
|
|
The same as ``...``. Special value used mostly in conjunction with extended
|
|
slicing syntax for user-defined container data types.
|
|
|
|
.. % XXX Someone who understands extended slicing should fill in here.
|
|
|