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| -rw-r--r-- | Doc/library/collections.rst | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index a891aff..58449fe 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -526,16 +526,7 @@ a fixed-width print format:: Point: x= 3.000 y= 4.000 hypot= 5.000 Point: x=14.000 y= 0.714 hypot=14.018 -Another use for subclassing is to replace performance critcal methods with -faster versions that bypass error-checking:: - - class Point(namedtuple('Point', 'x y')): - __slots__ = () - _make = classmethod(tuple.__new__) - def _replace(self, _map=map, **kwds): - return self._make(_map(kwds.get, ('x', 'y'), self)) - -The subclasses shown above set ``__slots__`` to an empty tuple. This keeps +The subclass shown above sets ``__slots__`` to an empty tuple. This keeps keep memory requirements low by preventing the creation of instance dictionaries. Subclassing is not useful for adding new, stored fields. Instead, simply |