python 高级特性：List Comprehensions

列表生成式: 创建List

格式：

        新列表 = [表达式/函数 for 变量 in 旧列表]

一、普通创建List

#!/usr/bin/python

#common establish way lis1 = []; for x in range(1, 10):     lis1.append(x); print "lis1:", lis1;

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二、列表生成式

#List comprehensions lis2 = [x for x in range(1, 10)] print "lis2:", lis2;

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#also can choose the even number in list lis3 = [x * x for x in range(1, 10) if x%2 == 0] print "lis3:", lis3;

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#two for in list lis4 = [x + y for x in 'ABC' for y in 'XYZ'] print "lis4:", lis4;

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#show the file in directory import os;     #导入OS模块 lis5 = [d for d in os.listdir('.')] print lis5;

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#convert all big_write string to small_write L = ['ABC', 'EFG', 'Hij', '8']   #只能为char类型，其他类型提示出错 lis6 = [s.lower() for s in L]   #lower()是内置函数，将大写转为小写 print lis6;

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