Commit f03f7c75 authored by Zachary Ware's avatar Zachary Ware

Closes #27204: Merge with 3.5

parents 1aa913e1 378a1d77
...@@ -1040,7 +1040,7 @@ If you use :func:`operator.add` with :func:`functools.reduce`, you'll add up all ...@@ -1040,7 +1040,7 @@ If you use :func:`operator.add` with :func:`functools.reduce`, you'll add up all
elements of the iterable. This case is so common that there's a special elements of the iterable. This case is so common that there's a special
built-in called :func:`sum` to compute it: built-in called :func:`sum` to compute it:
>>> import functools >>> import functools, operator
>>> functools.reduce(operator.add, [1,2,3,4], 0) >>> functools.reduce(operator.add, [1,2,3,4], 0)
10 10
>>> sum([1,2,3,4]) >>> sum([1,2,3,4])
......
.. testsetup::
import ipaddress
.. _ipaddress-howto: .. _ipaddress-howto:
*************************************** ***************************************
...@@ -49,11 +53,6 @@ to use the :func:`ipaddress.ip_address` factory function, which automatically ...@@ -49,11 +53,6 @@ to use the :func:`ipaddress.ip_address` factory function, which automatically
determines whether to create an IPv4 or IPv6 address based on the passed in determines whether to create an IPv4 or IPv6 address based on the passed in
value: value:
.. testsetup::
>>> import ipaddress
::
>>> ipaddress.ip_address('192.0.2.1') >>> ipaddress.ip_address('192.0.2.1')
IPv4Address('192.0.2.1') IPv4Address('192.0.2.1')
>>> ipaddress.ip_address('2001:DB8::1') >>> ipaddress.ip_address('2001:DB8::1')
......
...@@ -58,28 +58,28 @@ A common pattern is to sort complex objects using some of the object's indices ...@@ -58,28 +58,28 @@ A common pattern is to sort complex objects using some of the object's indices
as keys. For example: as keys. For example:
>>> student_tuples = [ >>> student_tuples = [
('john', 'A', 15), ... ('john', 'A', 15),
('jane', 'B', 12), ... ('jane', 'B', 12),
('dave', 'B', 10), ... ('dave', 'B', 10),
] ... ]
>>> sorted(student_tuples, key=lambda student: student[2]) # sort by age >>> sorted(student_tuples, key=lambda student: student[2]) # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
The same technique works for objects with named attributes. For example: The same technique works for objects with named attributes. For example:
>>> class Student: >>> class Student:
def __init__(self, name, grade, age): ... def __init__(self, name, grade, age):
self.name = name ... self.name = name
self.grade = grade ... self.grade = grade
self.age = age ... self.age = age
def __repr__(self): ... def __repr__(self):
return repr((self.name, self.grade, self.age)) ... return repr((self.name, self.grade, self.age))
>>> student_objects = [ >>> student_objects = [
Student('john', 'A', 15), ... Student('john', 'A', 15),
Student('jane', 'B', 12), ... Student('jane', 'B', 12),
Student('dave', 'B', 10), ... Student('dave', 'B', 10),
] ... ]
>>> sorted(student_objects, key=lambda student: student.age) # sort by age >>> sorted(student_objects, key=lambda student: student.age) # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
...@@ -208,15 +208,15 @@ return a negative value for less-than, return zero if they are equal, or return ...@@ -208,15 +208,15 @@ return a negative value for less-than, return zero if they are equal, or return
a positive value for greater-than. For example, we can do: a positive value for greater-than. For example, we can do:
>>> def numeric_compare(x, y): >>> def numeric_compare(x, y):
return x - y ... return x - y
>>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare) >>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare) # doctest: +SKIP
[1, 2, 3, 4, 5] [1, 2, 3, 4, 5]
Or you can reverse the order of comparison with: Or you can reverse the order of comparison with:
>>> def reverse_numeric(x, y): >>> def reverse_numeric(x, y):
return y - x ... return y - x
>>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric) >>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric) # doctest: +SKIP
[5, 4, 3, 2, 1] [5, 4, 3, 2, 1]
When porting code from Python 2.x to 3.x, the situation can arise when you have When porting code from Python 2.x to 3.x, the situation can arise when you have
...@@ -244,6 +244,12 @@ function. The following wrapper makes that easy to do:: ...@@ -244,6 +244,12 @@ function. The following wrapper makes that easy to do::
To convert to a key function, just wrap the old comparison function: To convert to a key function, just wrap the old comparison function:
.. testsetup::
from functools import cmp_to_key
.. doctest::
>>> sorted([5, 2, 4, 1, 3], key=cmp_to_key(reverse_numeric)) >>> sorted([5, 2, 4, 1, 3], key=cmp_to_key(reverse_numeric))
[5, 4, 3, 2, 1] [5, 4, 3, 2, 1]
......
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