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#16523: merge with 3.3.

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Ezio Melotti 2013-05-08 10:56:32 +03:00
commit 0fbdf26158
3 changed files with 43 additions and 24 deletions
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Doc/library/operator.rst
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@ -249,13 +249,22 @@ lookups. These are useful for making fast field extractors as arguments for
expect a function argument. expect a function argument.
.. function:: attrgetter(attr[, args...]) .. function:: attrgetter(attr)
attrgetter(*attrs)
Return a callable object that fetches *attr* from its operand. If more than one Return a callable object that fetches *attr* from its operand.
attribute is requested, returns a tuple of attributes. After, If more than one attribute is requested, returns a tuple of attributes.
``f = attrgetter('name')``, the call ``f(b)`` returns ``b.name``. After, The attribute names can also contain dots. For example:
``f = attrgetter('name', 'date')``, the call ``f(b)`` returns ``(b.name,
b.date)``. Equivalent to:: * After ``f = attrgetter('name')``, the call ``f(b)`` returns ``b.name``.
* After ``f = attrgetter('name', 'date')``, the call ``f(b)`` returns
``(b.name, b.date)``.
* After ``f = attrgetter('name.first', 'name.last')``, the call ``f(b)``
returns ``(r.name.first, r.name.last)``.
Equivalent to::
def attrgetter(*items): def attrgetter(*items):
if any(not isinstance(item, str) for item in items): if any(not isinstance(item, str) for item in items):
@ -275,14 +284,19 @@ expect a function argument.
return obj return obj
The attribute names can also contain dots; after ``f = attrgetter('date.month')``, .. function:: itemgetter(item)
the call ``f(b)`` returns ``b.date.month``. itemgetter(*items)
.. function:: itemgetter(item[, args...])
Return a callable object that fetches *item* from its operand using the Return a callable object that fetches *item* from its operand using the
operand's :meth:`__getitem__` method. If multiple items are specified, operand's :meth:`__getitem__` method. If multiple items are specified,
returns a tuple of lookup values. Equivalent to:: returns a tuple of lookup values. For example:
* After ``f = itemgetter(2)``, the call ``f(r)`` returns ``r[2]``.
* After ``g = itemgetter(2, 5, 3)``, the call ``g(r)`` returns
``(r[2], r[5], r[3])``.
Equivalent to::
def itemgetter(*items): def itemgetter(*items):
if len(items) == 1: if len(items) == 1:
@ -321,9 +335,14 @@ expect a function argument.
Return a callable object that calls the method *name* on its operand. If Return a callable object that calls the method *name* on its operand. If
additional arguments and/or keyword arguments are given, they will be given additional arguments and/or keyword arguments are given, they will be given
to the method as well. After ``f = methodcaller('name')``, the call ``f(b)`` to the method as well. For example:
returns ``b.name()``. After ``f = methodcaller('name', 'foo', bar=1)``, the
call ``f(b)`` returns ``b.name('foo', bar=1)``. Equivalent to:: * After ``f = methodcaller('name')``, the call ``f(b)`` returns ``b.name()``.
* After ``f = methodcaller('name', 'foo', bar=1)``, the call ``f(b)``
returns ``b.name('foo', bar=1)``.
Equivalent to::
def methodcaller(name, *args, **kwargs): def methodcaller(name, *args, **kwargs):
def caller(obj): def caller(obj):