Python-------字符串操作

# !/usr/bin/env python# -*- coding: utf-8 -*-# Author: Justin Channame = 'my \t name is {name} and i am {year} old'print(name.capitalize())#首字母大写print(name.isdigit())#数字判断print(name.count('a'))#统计字符个数print(name.center(50,'-'))#一共需要打印50个字符，如果不够‘-’补上print(name.ljust(50,'*'))#保证name字串长度为50,如果不够用‘×’右边补上print(name.rjust(50,'*'))#保证name字串长度为50,如果不够用‘×’左边补上print(name.encode())#编码，转换成二进制数print(name.endswith('ld'))#判断是否以'ld'结尾print(name.expandtabs(tabsize=10))#设置tab键转成10个空格print(name.find('old'))#找到’old‘的启始位置print(name.format(name='Justin',year=18))#格式化输出，替换name和yearprint(name.format_map({'name':'Justin','year':12}))#与format类似，传入的是字典print('123'.isalnum())#’123‘是否是阿拉伯数字，如果有一个非阿拉伯数字返回falseprint('afd'.isalpha())#’afd‘是否是阿拉伯字母，如果有一个非阿拉伯字母返回falseprint('1a'.isdecimal())#'la'是否是10进制print('3AB'.isidentifier())#判断是不是一个合法的标识符，即是不是一个合法的变量名，不是数字和非法字符开头print('fafs'.islower())#判断是不是小写、print('fafs'.isupper())#判断是不是大写print('2541.33'.isnumeric())#判断是不是数字，’.‘字符也不行，纯数字print('My name'.istitle())print('My name'.isprintable())#是否可以打印，is tty file or drive file is not printableprint('+'.join(['1','2','3','4']))#用+号把列表的内容隔开print('afKFDS'.lower())#把大写转小写print('afKFDS'.upper())#把小写转大写print('Justin Chan\n'.strip())#去掉空格和回车print('\n Justin Chan \n'.lstrip())#去掉左边的空格和回车print('\n Justin Chan\n'.rstrip())#去掉右边的空格和回车p = str.maketrans('fajufsi','1234567')print('Justin'.translate(p))#有点加密的味道，把'fajufsi'和'1234567'每个字符一一对应起来，传入p，把‘Justin’其中出现的字符替换掉。print('JUSTIN'.replace('USTIN','ustin',1))#替换print('Justin Chan'.rfind('n'))#从左往右查找‘n’，找到最右边的索引。print('Justin Chan'.split('n'))#把'n'当作分隔符，分割'Justin Chan'，并输出列表中print('Justin Chan'.swapcase())#字母大小写互换print('justin Chan'.title())#转换为标题，标题首字母大写print('justin Chan'.zfill(15))#长度不够，用zero填充

输出：

My   name is {name} and i am {year} oldFalse5-----my      name is {name} and i am {year} old------my   name is {name} and i am {year} old**********************my    name is {name} and i am {year} oldb'my \t name is {name} and i am {year} old'Truemy         name is {name} and i am {year} old36my   name is Justin and i am 18 oldmy   name is Justin and i am 12 oldTrueTrueFalseFalseTrueFalseFalseFalseTrue1+2+3+4afkfdsAFKFDSJustin ChanJustin Chan  Justin ChanJ46t7nJustin10['Justi', ' Cha', '']jUSTIN cHANJustin Chan0000justin Chan

字符运算符参与字符运算

可以使用 > < ==参与到字符串的运算，原理是根据字符串中每个字符的ASCII或Unicode码值逐个字符比较大小。

>>> print("abc" < "acc")True