String:
" "
‘‘‘ ‘‘‘
‘ ‘
Ordered indexable sql= "select" Sql[4]=c
Iterate lst=list (SQL) =["s", "E", "L", "E", "C", "T"]
String connection: "Connector". Join (the element is an iterative object of type String)------> return a new string
String connection: "str1" + "STR2"------> Returns a new string
String splitting: "string". Split (["Delimiter =none"],[maxsplit=-1])-------> return element is a list of string types None white space character: "\ r \ n \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1
"String". Rsplit ("[Sep=none]", [maxsplit=-1])------> cut from the right, returns an element that is a string of type list None white space character: "\ n \ t \r,-1 by default it can cut a few knives
"String". Splitline ("Sep=none", maxsplit)-----> return element is a list of string types None line break: \ n \r-1 The default is to cut a few knives.
String segmentation: "". partition (["Sep=none"])-------> return element is a tuple of string type (Head.sep.tail) None white space character: "\ t \ n \ r
"String". Partition ("Sep")-------> return element is a tuple of string type (Head.sep.tail) delimiter must be specified to keep the delimiter cut into two parts divided into three segments
"String". Partition ("Sep")-------> Start cutting from the right. The return element is a tuple of string type (Head.sep.tail) delimiter must be specified to cut a knife delimiter to remain cut into two parts divided into three sections
String modification: "string". Replace (Old,new,[count])----> Returns a new string
"String". Strip ([chars])----> Returns a new string
String lookup: "string". Find (Sub,[start,stop])-----> Return index number, cannot find return-1
"String". RFind (Sub,[start,stop])-----> Find from right, return index number, cannot find return-1
"String". Index (Sub,[start,stop])-----> Return index number, return index number, no error found
"String". Rindex (Sub,[start,stop])-----> Search from the right, return index number, return index number, no error found
String length: Len ("str")----->int length
String count: Count ("str", [start,stop])-----> occurrences
String judgment: "". StartsWith (Sub,[start,stop])----->bool
"". EndsWith (Sub,[start,stop])------>bool
String case: "". Lower ()
"". Upper ()
"". Title ()
". Capitalize ()
String is series
"String". Isalnum ()----->bool is not just numbers and letters
"String". Isalpha ()----->bool is not only the alphabet
"String". IsDigit ()------>bool is not just a number
"String". Isupper ()------->bool is not a word embox uppercase
"String". Islower ()-------->bool is not a word embox lowercase
"String". Isspace ()------->bool are not all whitespace characters
"String". Isdentifier ()------>bool is not the identifier letter and the underscore begins with other alphanumeric underscores
字符串格式化---format函数"{}{***}".format(*args,**kwargs)----->str:<左对齐 > 默认右对齐 ^居中：2 宽度为2 ：0>2 填充 宽度为2 其余用0填充：.2f 浮点数 精度为2 四舍五入：3.3%：d 十进制：x 十六进制：o 八进制：b 二进制
Python data Structure-string
