python 字符串所有操作

参考链接： Python字符串 replace

python字符串操作: 

字符串一般常用操作: 

 字符串的替换、删除、截取、复制、连接、比较、查找、分割等 

字符串内置操作方法: 

 使用type获取创建对象的类 type(name) 使用dir获取类的成员dir(name) 使用vars获取类的成员和各个成员的值 

字符串常用方法操作: 

1:casefold()将所有的字符转化为小写: 

name = "ZhangSan"

print("{0}".format(name.casefold()))

# 打印结果:zhangsan

2:capitalize()字符串首字母大写其他字符都小写: 

name = "zhangSan"

name = name.capitalize()

print("{0}".format(name))

# 打印结果:Zhangsan

3:center()字符串宽度填充: 

name = "zhangSan"

name = name.center(12)

print("{0}".format(name))

# 打印结果:'  Zhangsan  '

# 默认以空格填充

name = "zhangSan"

name = name.center(12, "#")

print("{0}".format(name))

# 打印结果:'##Zhangsan##'

# 以‘#’填充

4:count()统计字符在字符串中出现的次数: 

name = "zhangSan"

num = name.count('S')

print("{0}".format(num))

# 打印结果:1

name = "zhangSan"

num = name.count('S', 0, 3) #从0，1，2索引里找

print("{0}".format(num))

# 打印结果:0

5:encode()字符串编码: 

name = "zhangsan"

name = name.encode('gbk')

print("{0}".format(name))

# 打印结果:b'zhangsan'

6:startswith()判断字符串以某个字符串开头，返回boolean类型: 

name = "zhangsan"

isTrue = name.startswith("zh")

print(isTrue)

# 打印结果:True

7:endswith()判断字符串以某个字符串结尾，返回boolean类型: 

name = "zhangsan"

isTrue = name.endswith("san")

print(isTrue)

# 打印结果:True

8:find()在字符串中查找指定字符串，找不到时返回-1: 

name = "zhangsan"

isIn = name.find("an")

print(isIn)

# 打印结果:2

# 返回字符串开始的下标

9:format()格式化输出字符串: 

name = "{} {} zhangsan" #"{} {}"是占位符，用下边format()里边的参数填充

name = name.format('I', 'am')

print(name)

# 打印结果:I am zhangsan

10:index()在字符串中查找指定的字符串,找不到时直接报错: 

name = "zhangsan"

isIn = name.index('h')

print(isIn)

# 打印结果:1

11:join()字符串连接： 

name = "zhangsan"

name = '*'.join(name)

print(name)

# 打印结果:z*h*a*n*g*s*a*n

12:isalnum()判断字符串是否包含字母数字字符： 

name = "zhangsan1"

isTrue = name.isalnum()

print(isTrue)

# 打印结果:True

name = "zhangsan1*"

isTrue = name.isalnum()

print(isTrue)

# 打印结果:False

13:isalpha()判断是否只包含字母: 

name = "zhangsan"

isTrue = name.isalpha()

print(isTrue)

# 打印结果:True

name = "zhangsan1"

isTrue = name.isalpha()

print(isTrue)

# 打印结果:False

14:isdigit()判断字符串只由数字构成: 

name = "1234"

isTrue = name.isdigit()

print(isTrue)

# 打印结果:True

name = "zhangsan1234"

isTrue = name.isdigit()

print(isTrue)

# 打印结果:False

15:isspace()判断字符串是否是空格: 

name = " "

isTrue = name.isspace()

print(isTrue)

# 打印结果:True

name = "zhang san"

isTrue = name.isspase()

print(isTrue)

# 打印结果:False

16:isupper()判断字符串是否全是大写字符: 

name = "ZHANGSAN"

isTrue = name.isupper()

print(isTrue)

# 打印结果:True

17:lower()将所有的大写字符转为小写字符: 

name = "ZHANGSAN"

name = name.lower()

print(name)

# 打印结果:zhangsan

18:lstrip()去除字符串左边的空格: 

name = "   zhangsan  "

name = name.lstrip()

print(name)

# 打印结果:zhangsan  

19:rstrip()去除字符串右边的空格: 

name = "   zhangsan  "

name = name.rstrip()

print(name)

# 打印结果:   zhangsan

20:去除字符串2边的空格: 

name = "   zhangsan   "

name = name.strip()

print(name)

# 打印结果:zhangsan

21:replace()字符串替换: 

name = "zhangsan"

name = name.replace("zhang", "li")

print(name)

# 打印结果:lisan

22:split()字符串分割，默认是空格: 

name = "zhang san"

name = name.split()

print(name)

# 打印结果:['zhang', 'san']

23:add()在字符串后边添加字符串: 

name = "zhang"

name = name.__add__("san")

print(name)

# 打印结果:zhangsan

24:contains()判断指定字符串是否包含在字符串中: 

name = "zhangsan"

isTrue = name.__contains__("san")

print(isTrue)

# 打印结果:True

25:eq（）判断字符串是否相等: 

name = "zhangsan"

name1 = "zhangsan"

isEq = name.__eq__(name1)

print(isEq)

# 打印结果:True