Closes #27204: Merge with 3.5
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@ -1040,7 +1040,7 @@ If you use :func:`operator.add` with :func:`functools.reduce`, you'll add up all
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elements of the iterable. This case is so common that there's a special
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built-in called :func:`sum` to compute it:
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>>> import functools
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>>> import functools, operator
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>>> functools.reduce(operator.add, [1,2,3,4], 0)
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10
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>>> sum([1,2,3,4])
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@ -1,3 +1,7 @@
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.. testsetup::
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import ipaddress
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.. _ipaddress-howto:
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***************************************
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@ -49,11 +53,6 @@ to use the :func:`ipaddress.ip_address` factory function, which automatically
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determines whether to create an IPv4 or IPv6 address based on the passed in
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value:
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.. testsetup::
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>>> import ipaddress
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::
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>>> ipaddress.ip_address('192.0.2.1')
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IPv4Address('192.0.2.1')
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>>> ipaddress.ip_address('2001:DB8::1')
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@ -58,28 +58,28 @@ A common pattern is to sort complex objects using some of the object's indices
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as keys. For example:
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>>> student_tuples = [
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('john', 'A', 15),
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('jane', 'B', 12),
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('dave', 'B', 10),
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]
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... ('john', 'A', 15),
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... ('jane', 'B', 12),
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... ('dave', 'B', 10),
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... ]
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>>> sorted(student_tuples, key=lambda student: student[2]) # sort by age
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[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
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The same technique works for objects with named attributes. For example:
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>>> class Student:
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def __init__(self, name, grade, age):
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self.name = name
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self.grade = grade
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self.age = age
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def __repr__(self):
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return repr((self.name, self.grade, self.age))
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... def __init__(self, name, grade, age):
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... self.name = name
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... self.grade = grade
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... self.age = age
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... def __repr__(self):
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... return repr((self.name, self.grade, self.age))
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>>> student_objects = [
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Student('john', 'A', 15),
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Student('jane', 'B', 12),
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Student('dave', 'B', 10),
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]
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... Student('john', 'A', 15),
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... Student('jane', 'B', 12),
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... Student('dave', 'B', 10),
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... ]
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>>> sorted(student_objects, key=lambda student: student.age) # sort by age
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[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
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@ -208,15 +208,15 @@ return a negative value for less-than, return zero if they are equal, or return
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a positive value for greater-than. For example, we can do:
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>>> def numeric_compare(x, y):
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return x - y
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>>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare)
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... return x - y
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>>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare) # doctest: +SKIP
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[1, 2, 3, 4, 5]
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Or you can reverse the order of comparison with:
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>>> def reverse_numeric(x, y):
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return y - x
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>>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric)
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... return y - x
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>>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric) # doctest: +SKIP
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[5, 4, 3, 2, 1]
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When porting code from Python 2.x to 3.x, the situation can arise when you have
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@ -244,6 +244,12 @@ function. The following wrapper makes that easy to do::
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To convert to a key function, just wrap the old comparison function:
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.. testsetup::
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from functools import cmp_to_key
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.. doctest::
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>>> sorted([5, 2, 4, 1, 3], key=cmp_to_key(reverse_numeric))
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[5, 4, 3, 2, 1]
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