是以单引号或双引号括起来的任意文本如：
string1 = 'abc'string2 = "cde"
字符串是不可变的，即以下尝试修改字符串的做法是错误的：
string = 'admin' string[0] = 'b'#会报出异常--TypeError: 'str' object does not support item assignment
len()--返回字符串的长度 print(len("sunck is a good man!"))#20
lower()--转换字符串中大写字母为小写字母 string="SUNCK is A Good Man" print('string=%s'% string.lower())#string=sunck is a good man
upper()--将字符串所有小写字母转换成大写字母 string="SuNck Is a gOOd man" print(string.upper())#SUNCK IS A GOOD MAN
swapcase()--转换字符串中字母的大小写 string="SuNck Is a gOOd man" print(string.swapcase())#sUnCK iS A GooD MAN
capitalize()--最首字母大写，其他小写 string="SuNck Is a gOOd man" print(string.capitalize())#Sunck is a good man
title()--每个单词首字母大写 string="SuNck Is a gOOd man" print(string.title())#Sunck Is A Good Man
center(width,fillchar)--字符串居中两边填充fillchar(默认空格)宽为width string="SuNck Is a gOOd man" print(string.center(40,"*"))#**********SuNck Is a gOOd man***********
ljust(width[,fillchar])--返回一个指定宽度的左对齐字符串，fillchar为填充字符,填在右边 string="SuNck Is a gOOd man" print(string.ljust(40,"%"))#SuNck Is a gOOd man%%%%%%%%%%%%%%%%%%%%%
rjust(width[,fillchar])--返回一个指定宽度的有=右对齐字符串，fillchar为填充字符,填在左边 string='you are nice man' print(string.rjust(40,'*'))#************************you are nice man
zfill(width)--返回一个长度为width的字符串，原字符串右对齐，前面补0 string='she was beautiful' print(string.zfill(40)) #00000000000000000000000she was beautiful
count(str[,start][,end])--返回字符串中str出现次数，可指定范围 string='he is very very handsome' print(string.count('very')) #2
find(str[,start][,end])--检测str字符串是否在字符串中，返回第一次出现的开始下标，没有返回-1 string='he is very very handsome' print(string.find('very'))#6
rfind(str[,start][,end])--从右检测str字符串是否在字符串中，返回第一次出现的开始下标，没有返回-1 string='he is very very handsome' print(string.rfind('very')) #11
index(str,start=0,end=len(str))--跟find（）一样，只不过如果str不存在会返回异常 string='kaige is a very very nice man' print(string.index('very')) #11
rindex(str,start=0,end=len(str))--跟index（）一样，只不过从右开始检索 string='kaige is a very very nice man' print(string.rindex('very')) #16
lstrip()--截掉字符串左侧指定的字符，默认为空格 string='******kaige is a very nice man' print(string.lstrip('*')) #kaige is a very nice man rstrip()--截掉字符串右侧指定的字符，默认为空格 string='******kaige is a very nice man*****' print(string.rstrip('*')) #******kaige is a very nice man
strip(str)--截去字符串两边str string='********kaige is a very nice man******' print(string.strip('*') #kaige is a very nice man
split(str='',num)--以str为分隔符截取字符串，指定截num个。 string="sunck**is*****a***good*man" list_=string.split("*") print(list_)#['sunck', '', 'is', '', '', '', '', 'a', '', '', 'good', 'man']
splitlines([keepends])--按照（‘\r’，‘\r\n’，‘\n’）分隔,keepends=True ，会保留换行符。默认为False string='''sunck is a good man! sunck is a handsomoe man! sunck is a nice man! ''' print(string.splitlines()) #['sunck is a good man!', 'sunck is a handsomoe man!', 'sunck is a nice man!']
join(seq)--以指定的字符串分隔符，将seq中的所有元素组合 list_=['sunck','is','a','good','man'] str2="*".join(list_) print(str2) #sunck*is*a*good*man
max()、min()--它们作用于字符串是以ascii码表顺序比较大小 max('a','A') #'a'
replace(oldstr,newstr,count)--用newstr替换oldstr,默认是全部替换。如果指定了count，那么就替换前count个 string="sunck is a good good good man" string=string.replace("good","nice",1) print(string) #sunck is a nice good good man
startswith(str,start=0,end=len(str))--判断在给定的范围内是否以给定的字符串开头，如果没有给定范围， 则默认整个字符串 string="sunck is a nice man" print(string.startswith('sunck'))#True print(string.startswith("sunck",5,16)#False
endswith(str,start=0,end=len(str))--判断在给定的范围内是否以给定的字符串结尾，如果没有给定范围， 则默认整个字符串 string="sunck is a great man" print(string.endswith("man")) #True
encode(encoding="utf-8",errors="strict")--编码 string="sunck is a good man" data=string.encode("utf-8") print(data) #b'sunck is a good man'
decode()--解码 注意：要与编码的格式一致 string="sunck is a good man" data=string.encode("utf-8") string=data.decode("utf-8") print(string) #sunck is a good man
isalpha()--如果字符串中至少有一个字符，且所有字符都是字母返回True,否则为False string="sunckisagoodman" print(string.isalpha()) #True
isalnum()--如果字符串中至少有一个字符，且所有字符都是字母或数字返回True,否则返回False string="1a2b3" print(string.isalnum()) #True
isupper()--如果字符串字至少有一个英文字符且所有英文字符都是大写返回True，否则为False print("AB#C".isupper())#True print("1".isupper())#False
islower()--如果字符串字至少有一个英文字符且所有英文字符都是小写返回True，否则为False print("abcA".islower())#False print("1".islower())#False print("abc".islower())#True istitle()--如果字符串是标题化的返回True,否则返回False print("Sunck Is".istitle())#True print("Sunck is".istitle())#False
isdigit()--如果字符串中只包含数字字符返回True,否则返回False print("123".isdigit())#True print("123a".isdigit())#False
isnumeric()--同上 print("123".isnumeric())#True print("123a".isnumeric())#True
isdecimal()--字符串只包含十进制字符 print("123".isdecimal())#True print("123a".isdecimal())#False
isspace()--如果字符只包含空格返回True,否则返回False print(" ".isspace())#True print(" \t".isspace())#True
转载于:https://www.cnblogs.com/byadmin/articles/foundation-1.html
