本文实例讲述了Python实现字典排序、按照list中字典的某个key排序的方法。分享给大家供大家参考，具体如下：
1.给字典按照value按照从大到小排序
排序
dict = {'a':21, 'b':5, 'c':3, 'd':54, 'e':74, 'f':0}
new_dict = sorted(dict.iteritems(), key=lambda d:d[1], reverse = True)
print new_dict
输出：
[('e', 74), ('d', 54), ('a', 21), ('b', 5), ('c', 3), ('f', 0)]
2. python按照list中的字典的某key排序:
例子:
s=[
{"no":28,"score":90},
{"no":25,"score":90},
{"no":1,"score":100},
{"no":2,"score":20},
]
print "original s: ",s
# 单级排序，仅按照score排序
new_s = sorted(s,key = lambda e:e.__getitem__('score'))
print "new s: ", new_s
# 多级排序,先按照score，再按照no排序
new_s_2 = sorted(new_s,key = lambda e:(e.__getitem__('score'),e.__getitem__('no')))
print "new_s_2: ", new_s_2
输出:
original s: [{'score': 90, 'no': 28}, {'score': 90, 'no': 25}, {'score': 100, 'no': 1}, {'score': 20, 'no': 2}]
new s: [{'score': 20, 'no': 2}, {'score': 90, 'no': 28}, {'score': 90, 'no': 25}, {'score': 100, 'no': 1}]
new_s_2: [{'score': 20, 'no': 2}, {'score': 90, 'no': 25}, {'score': 90, 'no': 28}, {'score': 100, 'no': 1}]
说明
1.new_s和new_s2的区别在于当score均为90的时候,重新按照no排序
2.顺序为从小到大,若在sorted函数的参数加上reverse = True则为从大到小
PS：这里再为大家推荐一款关于排序的演示工具供大家参考：
在线动画演示插入/选择/冒泡/归并/希尔/快速排序算法过程工具：
http://tools.softyun.net/aideddesign/paixu_ys
希望本文所述对大家Python程序设计有所帮助。
