Python推导式简单示例【列表推导式、字典推导式与集合推导式】_Python

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)}

									>>> set1

									set([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

Python推导式简单示例【列表推导式、字典推导式与集合推导式】

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