python3字符串的功能举例详细说明

s1 ='Hello'
s2 = s1.__add__(' boy!')
print(s2)

#输出：Hello boy!

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

#输出：True

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

#输出：False

print('abc'.len())#输出：3

print('b'.le('a'))#输出：False

print('b'.lt('a'))#输出：False

print('abc'.__str__())
#输出：abc

s = 
'tom'print(s.capitalize())
#输出：Tom

s = 
'TOM'print(s.casefold())#
输出：tom

s =
 'Tom'print(s.center(20,'-'))
 #输出：--------Tom---------

s = 
'aabbbcccccdd'print(s.count('cc',3,11))
#输出：2

s = 
"中文"print(s.encode('gbk'))
#输出：b'\xd6\xd0\xce\xc4'

s = 
'Projects'print(s.endswith('ts'))print(s.endswith('e',0,5))
#输出：True#     True

s = 
'H\ti'print(s.expandtabs())
#输出：H       i

s = 
'Hello'print(s.find('o'))print(s.find('o',0,3))  
#找不到返回-1#输出：4#     -1

name = 
'Tom'age = 18s = '{0}\'s age is {1}'.format(name,age)print(s)
#或者str = '{name}\'s age is {age}'result = str.format(age=18,name='Tom')print(result)
#输出：Tom's age is 18

s = 'Hello'print(s.index('o'))print(s.index('e',0,3))
#输出：4#     1

s = '!#'print(s.isalnum())
#输出：False

s = '123'print(s.isalpha())
#输出：False

s = '123'print(s.isdecimal())
#输出：True#True: Unicode数字，，全角数字（双字节）#False: 罗马数字，汉字数字#Error: byte数字（单字节）

s = '123'print(s.isdigit())
#输出：True#True: Unicode数字，byte数字（单字节），全角数字（双字节），罗马数字#False: 汉字数字

s = '1num'print(s.isidentifier())
#输出：False#因为变量名不能以数字开头

s = 'Hello'print(s.islower())
#输出：False

s = '123'print(s.isnumeric())
#输出：True#True: Unicode数字，全角数字（双字节），罗马数字，汉字数字

s = '\n'print(s.isprintable())
#输出：False

print(' '.isspace())print('\t'.isspace())
#输出：True#     True

print('Hello Boy'.istitle())print('hello boy'.istitle())
#输出：True#     False

print('BOY'.isupper())print('Boy'.isupper())
#输出：True#     False

s = ['H','e','l','l','o']print(''.join(s))print('-'.join(s))
#输出：Hello#     H-e-l-l-o

s = 'Hello'print(s.ljust(10,'-'))
#输出：Hello-----

s = 'TOM'print(s.lower())
#输出：tom

s = '   Tom'print(s.lstrip())
#输出：Tom

s = 'IamTom'print(s.partition('am'))
#输出：('I', 'am', 'Tom')

s = 'Tom'print(s.replace('m','o'))
#输出：Too

s = 'one two one'print(s.rfind('one'))print(s.rfind('one',0,6))  
#指定起始和结束位置#输出：8#     0

s = 'one two one'print(s.rindex('one'))print(s.rindex('one',0,6))  
#指定起始和结束位置#输出：8#     0

s = 'Hello'print(s.rjust(10,'-'))
#输出：-----Hello

s = 'IamTom_IamTom'print(s.rpartition('am'))
#输出：('IamTom_I', 'am', 'Tom')

s = 'a b c d'print(s.rsplit())print(s.rsplit(' ',2))  
#从右边开始，按空格分隔两次#输出：['a', 'b', 'c', 'd']
#     ['a b', 'c', 'd']

s = '!!! I am Tom !!!'print(s.rstrip('!'))
#输出：!!! I am Tom

s = 'a b c d'print(s.split())print(s.split(' ',2)) 
#从左边开始，按空格分隔两次#输出：['a', 'b', 'c', 'd']#    ['a', 'b', 'c d']

s = 'a\nb\nc'print(s.splitlines())    
#默认参数为Falseprint(s.splitlines(True)) 
#指定Ture参数，则保留换行符#输出：['a', 'b', 'c']
#     ['a\n', 'b\n', 'c']

s = 'Projects'print(s.startswith('Pr'))print(s.startswith('e',4,8))
#输出：True#     True

s = '!!! I am Tom !!!'print(s.strip('!'))
#输出： I am Tom

s = 'I am Tom'print(s.swapcase())
#输出：i AM tOM

s = 'i am tom'print(s.title())
#输出：I Am Tom

s = 'Hello'print(s.upper())
#输出：HELLO

s = 'Hello'print(s.zfill(10))
# 输出：00000Hello