字符串

>>> a='abcdefg'
>>> a
'abcdefg'
>>> a[::-2]
'geca'
>>> a[::]
'abcdefg'
>>> a[::-1]
'gfedcba'
>>> a = 'abcdef'
>>> a
'abcdef'
>>> a[::-1]
'fedcba'
>>> a
'abcdef'
>>> a[4:3]
''
>>> a[4:3:-1]
'e'



>>> mystr = 'hello world wanglinjie linjie w_linjie'
>>> mystr.find("linjie")
16
>>> mystr.find("linjie",0,10)
-1
>>> mystr.count("linjie")
3

>>> mystr.replace("linjie","LinJie")
'hello world wangLinJie LinJie w_LinJie'


>>> mystr.replace("linjie","LinJie",1)
'hello world wangLinJie linjie w_linjie'
>>> mystr.split(" ")
['hello', 'world', 'wanglinjie', 'linjie', 'w_linjie']

>>> mystr.split(" ",2)
['hello', 'world', 'wanglinjie linjie w_linjie']

>>> mystr.split(" ",3)
['hello', 'world', 'wanglinjie', 'linjie w_linjie']

>>> mystr.capitalize()
'Hello world wanglinjie linjie w_linjie'

>>> mystr.title()
'Hello World Wanglinjie Linjie W_Linjie'
>>> mystr.startswith("hello")
True
>>> mystr.startswith("Hello")
False
>>> mystr.endswith("jie")
True
>>> mystr.endswith("Jie")
False
>>> 

>>> Mystr=ystr = 'Hello World Wanglinjie Linjie W_Linjie'
>>> Mystr.lower()
'hello world wanglinjie linjie w_linjie'
>>> 

>>> Mystr=ystr = 'Hello World Wanglinjie Linjie W_Linjie'

>>> Mystr.lower()
'hello world wanglinjie linjie w_linjie'

>>> Mystr.upper()
'HELLO WORLD WANGLINJIE LINJIE W_LINJIE'

>>> Mystr.ljust(10)
'Hello World Wanglinjie Linjie W_Linjie'

>>> my = 'wang'
>>> my.ljust(10)
'wang      '>>> mystr.rjust(10)
'hello world wanglinjie linjie w_linjie'
>>> my.rjust(10)
'      wang'
>>> mystr.center(10)
'hello world wanglinjie linjie w_linjie'
>>> my.center(10)
'   wang   '
>>> my.lstrip()
'wang'
>>> a = '     linjie     '
>>> a.lstrip()
'linjie     '
>>> a.rstrip()
'     linjie'
>>> a.strip()
'linjie'
>>> 

>>> mystr
'hello world wanglinjie linjie w_linjie'
>>> mystr.rfind("linjie")
32
>>> mystr.partition("linjie")
('hello world wang', 'linjie', ' linjie w_linjie')
>>> mystr.rpartition("linjie")
('hello world wanglinjie linjie w_', 'linjie', '')

>>> mystr = 'abc'
>>> mystr.isalpha()
True
>>> mystr.isdigit()
False
>>> mystr1 = '123'
>>> mystr1.isalpha()
False
>>> mystr1.isdigit()
True
>>> mystr2 = 'abc123'
>>> mystr2.isalnum()
True
>>> mystr1.isalnum()
True
>>> mystr.isalnum()
True
>>> mystr3 = ' '
>>> mystr3.isalnum()
False
>>> mystr3.isspace()
True

>>> mystr = ' '
>>> li = ["my","name","is","linjie"]>>> mystr.join(li)
'my name is linjie'
>>> a = '_'
>>> a.join(li)
'my_name_is_linjie'
>>>