zoukankan      html  css  js  c++  java
  • list 操作

    
    animals = ["aardvark", "badger", "duck", "emu", "fennec fox"]
    
    print(animals[1:3])    # print "badger" and "duck"
    
    duck_index = animals.index("duck")   # Use index() to find "duck"
    
    animals.insert(2,"cobra") #insert "cobra" at index 2,which move everything down by 1. #插入
    
    animals.remove("duck")  #删除"duck"
    
    # 遍历list
    
    my_list = [1,9,3,8,5,7]
    for number in my_list:  
        print(number * 2)    # print a number equal to 2 * for every list item
    
    for index, item in enumerate(my_list):
        print index , item  # 得到 index(从 0 开始) 和 my_list 的内容
    
    # 排序
    
    start_list = [5, 3, 1, 2, 4]
    str = ["bb","aa","AA","ac"]
    start_list.sort()
    str.sort()
    print(square_list)  #输出 1,2,3,4,5
    print(str)  #输出 "AA","aa","ac","bb"
    
    
    #删除
    list = [1,2,3,4,5]
    list.remove(value)  # 从list中删除value
    list.pop(index)     # 从list中删除下标为index的数(从0开始)
    del(list[index])    # 从list中删除下标为index的数(从0开始)
    
    #lis相加
    a = [1,2,3]
    b = [4,5,6]
    a + b  # 得到 [1,2,3,4,5,6]
    
    #同时比较多个list
    list_a = [3, 9, 17, 15, 19]
    list_b = [2, 4, 8, 10, 30, 40, 50, 60, 70, 80, 90]
    
    for a, b in zip(list_a, list_b):
        # 输出较大的数
        if a > b:
            print a
        else:
            print(b)
        # 得到 3,9,17,15,30
    
    # list comprehension (满足一定条件)
    doubles_by_3 = [x for x in range(0,10) if x % 2 == 0] #得到[0,2,4,6,8]
    even_squares = [x ** 2 for x in range(1,11) if x % 2 == 0] #得到[4,16,36,64,100]
    
    #Lambda Syntax (选择满足条件的)
    languages = ["HTML", "JavaScript", "Python", "Ruby"]
    print filter(lambda str : str == "Python", languages) #输出 "Python" 
    
    #选择某些下标对应的值
    print(list[start:end:step])
    #缺省start时默认从零开始,缺省end时默认到最后,缺省step时默认step=1
    #当step为正数时,从左到右;step为负数时,从右到左
    
    
  • 相关阅读:
    window10使用vagrant+virtualBox搭建centos7
    吾日三思
    搭建EFK过程
    docker端口映射失效解决方法
    centos7防火墙相关命令
    docker学习
    python 读取hive数据
    shell 命令 查看本机ip
    shell 命令 修改hosts文件
    shell 命令 mkdir -p
  • 原文地址:https://www.cnblogs.com/jxgapyw/p/5122765.html
Copyright © 2011-2022 走看看