Python之字符串基本操作

#!/usr/bin/env python#-*-coding utf8-*-#Author:caojininfo = {    ‘stu1001‘: ‘caojin‘,    ‘stu1002‘: ‘zhaoming‘,    ‘stu1003‘: ‘zhansan‘,    ‘stu1004‘: ‘lisi‘,}print(info)print(info[‘stu1002‘])info[‘stu1003‘] = "张山"  #修改print(info)info[‘st112‘] = "孙悟空" #如果没有则是添加print(info)del info[‘stu1004‘]     #删除print(info)info.pop(‘stu1003‘)     #删除print(info)info.popitem()      #随机删除print(info)print(info.get(‘stu00010‘))  #找元素，即便没有也没有错，出现noneprint(‘stu1001‘ in info)    #判断元素是否在print(‘stu1005‘ in info)

info.setdefault(‘stu1002‘,"贝吉塔")  #先去找1002这个元素，如果有，直接返回值；如果没有，则增加新的值print(info)

b = {    ‘stu1001‘:‘lengmengyun‘,    1:3,    3:5}print(b)info.update(b) #把列表b的元素放进info里面，如果有同样的序列，则元素被替换。交叉的覆盖了print(info)print(info.items()) #把字典转成了列表c = info.fromkeys([6,7,8])print(c)e = dict.fromkeys([6,7,8],"100")    #创建相同元素print(e)f = dict.fromkeys([6,7,8],[1,{"name":"caojin"},444])print(f)f[8][1][‘name‘] = "zhaoming"  #注意用fromkeys创建字典的守护，改一个则都改了print(f)print("-----",info,"------")for i in info:      #两个for效果一样，但是上面个高效，如果数据量上百万，下面个for循环可能会崩溃    print(i,info[i])for k,v in f.items():    print(k,v)