python 高級特性：List Comprehensions

• 2020 年 1 月 14 日
• 筆記

列表生成式: 創建List

格式：

        新列表 = [表達式/函數 for 變數 in 舊列表]

一、普通創建List

#!/usr/bin/python

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

二、列表生成式

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

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

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

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

#convert all big_write string to small_write L = ['ABC', 'EFG', 'Hij', '8']   #只能為char類型，其他類型提示出錯 lis6 = [s.lower() for s in L]   #lower()是內置函數，將大寫轉為小寫 print lis6;