1、join方法：拼接字符串------->str

a = "你是风儿我是沙"
b = "@".join(a)
print(b)
>>>你@是@风@儿@我@是@沙

2、strip方法：处理左右空格、\t、\n----->str
　　还可以处理指定内容a.strip("x") a.lstrip a.rstrip()

a = " Hello world"
b = a.strip()
print(b)
>>>Hello World

3、对应字符转化：str.maketrans/translate----->str

v = "abcdefghijklmnodsjjkkkee"#原字符串
m = str.maketrans("aeiou",'12345')#构造对应关系m
new_v = v.translate(m)#生成新关系
print(new_v)
>>>1bcd2fgh3jklmn4dsjjkkk22

4、partition字符串分割，分三段---->元祖

v = "abcdefghijklmnodsjjkkkee"
b = v.partition("s")
print(b)
>>>('abcdefghijklmnod', 's', 'jjkkkee')

5、split字符串分割，一刀两断，两刀三段，拿不到分割元素---->list

v = "   abcbdefbghijk   "
b = v.split()
c = v.split('b')
d = v.split('b',2)
print(1,b)
print(2,c)
print(3,d)
>>>1 ['abcbdefbghijk']
>>>2 ['   a', 'c', 'def', 'ghijk   ']
>>>3 ['   a', 'c', 'defbghijk   ']

6、splitlines按照\n进行分割----->list

a = "abcsjdfk\nfjsdjf\njdfkdj\nsdfsf"
b = a.splitlines()(参数可以是True/False是否保留\n)
print(b)
for i in b:#处理文本方式
　　print(i)
>>>['abcsjdfk', 'fjsdjf', 'jdfkdj', 'sdfsf']

7、find方法:返回int，第一个索引号

a = '123bcds'
b = a.find('b')
print(b,type(b))
>>>3 <class 'int'>

8、replace方法：
a = "11sb11we11gg11"
b = a.replace("11","@@",2)
print(b,type(b))
>>>@@sb@@we11gg11 <class 'str'>