Python - 字典按值(value)排序

字典安值排序是一个伪命题.
字典本身是不能被排序的, 已经按照关键字(key)排序, 但是列表(list)和元组(tuple)可以排序, 所以字典需要转换列表后排序.
如

import operatorx = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}sorted_x = sorted(x.items(), key=operator.itemgetter(1))

则是转换列表后的排序, dict(sorted_x) == x, 列表转换字典.

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代码

# -*- coding: utf-8 -*-import operatorx = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}# 根据值排序sorted_x = sorted(x.items(), key=operator.itemgetter(1))print 'x = ' + str(x)print 'sorted_x = ' + str(sorted_x)print 'dict(sorted_x) = ' + str(dict(sorted_x))x = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}sorted_x = sorted(x.items(), key=operator.itemgetter(0))print 'x = ' + str(x)print 'sorted_x = ' + str(sorted_x)print 'dict(sorted_x) = ' + str(dict(sorted_x))"""输出:x = {0: 0, 1: 2, 2: 1, 3: 4, 4: 3}sorted_x = [(0, 0), (2, 1), (1, 2), (4, 3), (3, 4)]dict(sorted_x) = {0: 0, 1: 2, 2: 1, 3: 4, 4: 3}x = {0: 0, 1: 2, 2: 1, 3: 4, 4: 3}sorted_x = [(0, 0), (1, 2), (2, 1), (3, 4), (4, 3)]dict(sorted_x) = {0: 0, 1: 2, 2: 1, 3: 4, 4: 3}"""

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