Python字典按值排序、包含字典的列表按字典值排序的方法
#-*- encoding=utf-8 -*-import operator#按字典值排序（默认为升序）x = {1:2, 3:4, 4:3, 2:1, 0:0}sorted_x = sorted(x.iteritems(), key=operator.itemgetter(1))print sorted_x#[(0, 0), (2, 1), (1, 2), (4, 3), (3, 4)]#如果要降序排序,可以指定reverse=Truesorted_x = sorted(x.iteritems(), key=operator.itemgetter(1), reverse=True)print sorted_x#[(3, 4), (4, 3), (1, 2), (2, 1), (0, 0)]#或者直接使用list的reverse方法将sorted_x顺序反转#sorted_x.reverse()#取代方法是,用lambda表达式sorted_x = sorted(x.iteritems(), key=lambda x : x[1])print sorted_x#[(0, 0), (2, 1), (1, 2), (4, 3), (3, 4)]sorted_x = sorted(x.iteritems(), key=lambda x : x[1], reverse=True)print sorted_x#[(3, 4), (4, 3), (1, 2), (2, 1), (0, 0)]#包含字典dict的列表list的排序方法与dict的排序类似,如下：x = [{'name':'Homer', 'age':39}, {'name':'Bart', 'age':10}]sorted_x = sorted(x, key=operator.itemgetter('name'))print sorted_x#[{'age': 10, 'name': 'Bart'}, {'age': 39, 'name': 'Homer'}]sorted_x = sorted(x, key=operator.itemgetter('name'), reverse=True)print sorted_x#[{'age': 39, 'name': 'Homer'}, {'age': 10, 'name': 'Bart'}]sorted_x = sorted(x, key=lambda x : x['name'])print sorted_x#[{'age': 10, 'name': 'Bart'}, {'age': 39, 'name': 'Homer'}]sorted_x = sorted(x, key=lambda x : x['name'], reverse=True)print sorted_x#[{'age': 39, 'name': 'Homer'}, {'age': 10, 'name': 'Bart'}]?