1 >>> s='i love cnblog'
2 >>> s.capitalize()
3 'I love cnblog'

1 >>> (s.capitalize()).casefold()
2 'i love cnblog'

1 >>> s.center(20)
2 '   i love cnblog    '

1 >>> s.count('0',5,13)
2 0
3 >>> s.count('o',5,13)
4 1
5 >>> s.count('o',0,13)
6 2

1 >>> s.encode(encoding='utf-8',errors='strict')
2 b'i love cnblog'

1 >>> s.encode()
2 b'i love cnblog'

1 >>> s.endswith('!',0,13)
2 False
3 >>> s.endswith('g')
4 True

1 >>> s.expandtabs()
2 'i love cnblog'
3 >>> s='\t i love cnblog\t'
4 >>> s.expandtabs()
5 '         i love cnblog  '

1 >>> s='i love cnblog'
2 >>> s.find('o')
3 3
4 >>> s.find('o',3,13)
5 3
6 >>> s.find('o',4,13)
7 11
8 >>> s.find('g',0,13)
9 12

1 >>> s='i love cnblog'
2 >>> s.index('o')
3 3
4 >>> s.index('h')
5 Traceback (most recent call last):
6   File "<pyshell#2>", line 1, in <module>
7     s.index('h')
8 ValueError: substring not found

 1 >>> s='i love cnblog'#有空格
 2 >>> s.isalnum()
 3 False
 4 >>> s='ilovecnblog'
 5 >>> s.isalnum()
 6 True
 7 >>> s='11ii'
 8 >>> s.isalnum()
 9 True

1 >>> s='ilovecnblog'
2 >>> s.isalpha()
3 True

1 >>> s='1234'
2 >>> s.isdigit()
3 True

>>> s='1234'
>>> s.isdecimal()
True
>>> s='ox12'#十六进制
>>> s.isdecimal()
False
>>> s='o123'#八进制
>>> s.isdigit()
False

1 >>> s='ilovecnblog'
2 >>> s.islower()
3 True
4 >>> s='ILOVE'
5 >>> s.isupper()
6 True

 1 >>> num='1'
 2 >>> num.isdigit()
 3 True
 4 >>> num.isnumeric()
 5 True
 6 >>> num=b'1'
 7 >>> num.isdigit()
 8 True
 9 >>> num.isnumeric()
10 Traceback (most recent call last):
11   File "<pyshell#31>", line 1, in <module>
12     num.isnumeric()
13 AttributeError: 'bytes' object has no attribute 'isnumeric'
14 >>> num='四'#汉字的数字，同样的还有罗马数字等
15 >>> num.isdigit()
16 False
17 >>> num.isnumeric()
18 True

'def'.isidentifier()
Out[3]:
True
'eval'.isidentifier()
Out[4]:
True

chr(1000000).isprintable()
Out[13]:
False

''.isspace()
Out[14]:
False
' '.isspace()
Out[15]:
True
' a'.isspace()
Out[16]:
False

'Author'.istitle()
Out[17]:
True
'aA'.istitle()
Out[18]:
False
'Aa'.istitle()
Out[19]:
True
'AAAa'.istitle()
Out[20]:
False

'AAAa'.isupper()
Out[21]:
False

a = '12345'
','.join(a)
Out[23]:
'1,2,3,4,5'

'AAA'.lower()
Out[24]:
'aaa'

b = 'a'.ljust(10)
len(b)
Out[28]:
10
'a'.ljust(10, 'A') # 指定以A填充
Out[30]:
'aAAAAAAAAA'

'ssaafdaf'.partition('f')
Out[3]:
('ssaa', 'f', 'daf')

'this is  a test'.replace('a', 'A')
Out[4]:
'this is  A test'

'this is a test'.rfind('i')
Out[5]:
5

'this is a test'.rindex('g')
Traceback (most recent call last):File "C:\Program Files\Python35\lib\site-packages\IPython\core\interactiveshell.py", line 2869, in run_codeexec(code_obj, self.user_global_ns, self.user_ns)File "<ipython-input-6-f8a393e6a7d2>", line 1, in <module>'this is a test'.rindex('g')
ValueError: substring not found

'aa'.ljust(10)
Out[25]:
'aa        '
'aa'.rjust(10)
Out[26]:
'        aa'

'this is a test'.rpartition('a')
Out[7]:
('this is ', 'a', ' test')

this is a test'.rsplit(' ')
Out[8]:
['this', 'is', 'a', 'test']

'this is a test'.split(' ', 1)
Out[10]:
['this', 'is a test']'this is a test'.rsplit(' ', 1)Out[11]: ['this is a', 'test']

'this is a test'.rstrip('t')
Out[12]:
'this is a tes'

'this is a test'.split('i', 1)
Out[13]:
['th', 's is a test']

'this is a string\n this is a test'.splitlines()
Out[14]:
['this is a string', ' this is a test']'this is a string\n this is a test'.splitlines(keepends=True)
Out[16]:
['this is a string\n', ' this is a test']

'this is a test'.startswith('t')
Out[18]:
True
# 不一定非得一单个字符
'this is a test'.startswith('this')
Out[19]:
True

'this is a test'.strip('ts')
Out[20]:
'his is a te'

'this is A test'.swapcase()
Out[21]:
'THIS IS a TEST'

'this is a test'.title()
Out[22]:
'This Is A Test'

'this is a test'.upper()
Out[24]:
'THIS IS A TEST'

'aa'.zfill(10)
Out[25]:
'00000000aa'