| |
| Built-in Constants |
| ================== |
| |
| A small number of constants live in the built-in namespace. They are: |
| |
| |
| .. data:: False |
| |
| The false value of the :class:`bool` type. |
| |
| .. versionadded:: 2.3 |
| |
| |
| .. data:: True |
| |
| The true value of the :class:`bool` type. |
| |
| .. versionadded:: 2.3 |
| |
| |
| .. 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 |
| |
| Special value used in conjunction with extended slicing syntax. |
| |
| .. % XXX Someone who understands extended slicing should fill in here. |
| |