Python笔记(四)字符串操作

Python中的字符串用法很多，很灵活，下面是一些常见字符串函数的用法.

#__author__ = "BoGe"print(''.join(['1','2','3']))#连接字符串print('ZhanGMing'.lower())#全部变小写print('zhangming'.upper())#全部变大写print('1+2+3+4'.split('+'))#根据+号分割成列表#------------------------------------------------------name = 'zhangming'print(name.capitalize())#字符串首字母大写name = 'ZHANGMING'print(name.casefold())#大写全部变小写print(name.center(50,"*"))#将name居中显示，左右两边用50个*对齐print(name.count('z'))#统计z出现的次数print(name.encode())#将字符串编码成byte格式print(b'ZHANGMING'.decode())#将字符串解码为UTF-8格式print(name.endswith('G'))#判断字符串是否以G结尾print('zhang\tming'.expandtabs(10))#将\t转换成10/2长的空格print(name.find('j'))#查找A,找到返回其索引，找不到返回-1#------------------------------------------------------#formatmsg = "my name is {}, and my age is {}"#格式化输出print(msg.format("zhangming",17))#将第一个字符串对应第一个{}msg = "my name is {1}, and my age is {0}"print(msg.format("zhangbo",22))#zhangbo代表0，22代表1msg = "my name is {0}, and my age is {1}"print(msg.format("zhangbo",22))#zhangbo代表0，22代表1msg = "my name is {name}, and my age is {age}"print(msg.format(age = 20, name = 'zhangming'))#字符串自动对应msg = "my name is {name}, and my age is {age}"print(msg.format_map({'name':'zhangming', 'age':19}))#和format一样，类似于字典#------------------------------------------------------print(msg.index('a'))#返回a所在字符串的索引print('123A'.isalnum())#是否为字母或数字print('9'.isdigit())#是否为整数name = 'ZHANGMING'print(name.isnumeric())#是否为数字print(name.isprintable())#是否可打印print(name.isspace())#判断是否为空或者转义字符print(name.istitle())#检索字符串中首字母是否为大写print(name.isupper())#检索字符串是否都为大写print("|".join(['张三','李四','王武']))#以|分割列表#------------------------------------------------------#maketransintab = 'thistreha'#字符串加密,将intab和outtab与str字符串进行映射得出加密字符串outtab = '123456789'#注:两个字符串长度必须一样，为一一对应关系transtab = str.maketrans(intab,outtab)str = "this is string test...HaHa!!!"print(str.translate(transtab))#------------------------------------------------------print(msg)print(msg.partition('is'))#通过is进行划分print('zhangli, chinese name is lijie'.replace("li","LI",2))#用一些字符替换一些字符string = 'zhangming'print(string.swapcase())#大小写互换print(string.zfill(40))#原字符串右对齐，前面填充0print(string.ljust(40,"-"))#把字符串长度变为40，并且用字符-填充print(string.rjust(40,'*'))b="abc_123"print(b.isidentifier())#检测一段字符是否符合变量名规则