本文实例讲述了Python推导式。分享给大家供大家参考，具体如下：
1. 列表推导式
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>>> li = [1,2,3,4,5,6]# 求元素的平方>>> li_a = [x**2 for x in li ]>>> li_a[1, 4, 9, 16, 25, 36]# 提取偶数值>>> li_b = [x for x in li if x%2==0]>>> li_b[2, 4, 6]# 将多维数组转换成一维数组>>> li_c = [[1,2], [3], [], [4,5,6]]>>> li_d = [j for i in li_c for j in i ]>>> li_d[1, 2, 3, 4, 5, 6]# 使用map>>> li_1 = ['a', 'b', 'c', 'd']>>> li_2 = [10, 20, 30, 40]>>> li_e = list(map(lambda x, y:{x:y}, li_1, li_2))>>> li_e[{'a': 10}, {'b': 20}, {'c': 30}, {'d': 40}] |
2. 字典推导式
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# 解析列表>>> li = ['a', 'b', 'c', 'd', 'e']>>> li_1 = {k:v for k, v in enumerate(li)}>>> li_1{0: 'a', 1: 'b', 2: 'c', 3: 'd', 4: 'e'}# 解析字典>>> dict_a = {'a':10, 'b':20, 'c':30}>>> dict_b = {v:k for k, v in dict_a.items()}>>> dict_b{10: 'a', 20: 'b', 30: 'c'} |
3. 集合推导式
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>>> set1 = {x for x in range(10)}>>> set1set([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) |
PS：上述代码在Python2.7与Python3.6环境下测试
希望本文所述对大家Python程序设计有所帮助。
原文链接：https://blog.csdn.net/baidu_32656897/article/details/82465861
