Python内置函数sorted()从入门到精通
Python内置函数sorted()从入门到精通
Python内置函数sorted()可以对列表、元组、字典、集合、字符串、range对象以及其他可迭代对象进行排序，返回排序后的列表，支持使用key参数指定排序规则，支持reverse参数指定升序或者降序。
>>> sorted(range(10)) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
#降序排列 >>> sorted(range(10), reverse=True) [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
#对字符串中的字符升序排序 >>> sorted('hello world') [' ', 'd', 'e', 'h', 'l', 'l', 'l', 'o', 'o', 'r', 'w'] >>> d = {'a':3, 'b':2, 'c':5, 'd':0}
#默认对字典中的键进行排序 >>> sorted(d) ['a', 'b', 'c', 'd'] >>> sorted(d.keys()) ['a', 'b', 'c', 'd']
#对字典中的值进行排序 >>> sorted(d.values()) [0, 2, 3, 5]
#对字典中的元素进行排序 >>> sorted(d.items()) [('a', 3), ('b', 2), ('c', 5), ('d', 0)]
>>> x = ['da', 'cc', 'aba', 'aec']
#按默认规则对字符串进行排序 >>> sorted(x) ['aba', 'aec', 'cc', 'da']
#按字符串长度进行排序 >>> sorted(x, key=len) ['da', 'cc', 'aba', 'aec']
#按字符串长度降序排序
>>> sorted(x, key=len, reverse=True) ['aba', 'aec', 'da', 'cc']
#按字符串长度降序排序
#注意负号的用法仅适用于数字 >>> sorted(x, key=lambda i:-len(i)) ['aba', 'aec', 'da', 'cc']
#按字符串下标为1的字符进行排序
>>> sorted(x, key=lambda i:i[1]) ['da', 'aba', 'cc', 'aec']
>>> from random import randint
#列表推导式，生成包含10个子列表的列表，每个子列表中包含10个随机数 >>> x = [[randint(1,10) for i in range(10)] for j in range(10)] >>> for item in x: print(item)
[4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10] [3, 2, 9, 2, 3, 5, 4, 8, 1, 3]
#对所有子列表进行排序 >>> for item in sorted(x): print(item)
[3, 2, 9, 2, 3, 5, 4, 8, 1, 3] [4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10]
#按每个子列表元素之和从小到大排序
>>> for item in sorted(x, key=sum):
print(sum(item), ':', item)
40 : [3, 2, 9, 2, 3, 5, 4, 8, 1, 3]
43 : [8, 6, 2, 4, 6, 2, 9, 3, 1, 2]
45 : [8, 2, 1, 3, 7, 4, 9, 1, 1, 9]
52 : [9, 2, 3, 1, 7, 4, 10, 1, 5, 10]
54 : [6, 2, 6, 6, 8, 6, 5, 2, 10, 3]
58 : [8, 8, 3, 1, 1, 8, 6, 10, 10, 3]
63 : [4, 10, 4, 6, 7, 9, 5, 1, 7, 10]
66 : [8, 3, 9, 2, 9, 8, 10, 7, 6, 4]
70 : [7, 10, 10, 3, 2, 7, 9, 10, 5, 7]
72 : [10, 5, 8, 10, 7, 1, 8, 10, 3, 10]
#按子列表中下标为1的元素进行排序 >>> for item in sorted(x, key=lambda i: i[1]): print(item)
[6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [3, 2, 9, 2, 3, 5, 4, 8, 1, 3] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7]
#按每个子列表前两项之和进行排序 >>> for item in sorted(x, key=lambda i: i[0]+i[1]): print(item)
[3, 2, 9, 2, 3, 5, 4, 8, 1, 3] [6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7]
#先按子列表中下标为0的元素排序
#如果下标为0的元素相等，再按下标为1的元素排序 >>> for item in sorted(x, key=lambda i: (i[0], i[1])): print(item)
[3, 2, 9, 2, 3, 5, 4, 8, 1, 3] [4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10]
#按所有子列表下标为0的元素升序、下标为1的元素降序进行排序 >>> for item in sorted(x, key=lambda i: (i[0], -i[1])): print(item)
[3, 2, 9, 2, 3, 5, 4, 8, 1, 3] [4, 10, 4, 6, 7, 9, 5, 1, 7, 10] [6, 2, 6, 6, 8, 6, 5, 2, 10, 3] [7, 10, 10, 3, 2, 7, 9, 10, 5, 7] [8, 8, 3, 1, 1, 8, 6, 10, 10, 3] [8, 6, 2, 4, 6, 2, 9, 3, 1, 2] [8, 3, 9, 2, 9, 8, 10, 7, 6, 4] [8, 2, 1, 3, 7, 4, 9, 1, 1, 9] [9, 2, 3, 1, 7, 4, 10, 1, 5, 10] [10, 5, 8, 10, 7, 1, 8, 10, 3, 10]