python正則表達式3-模式匹配

re.S，使 '.'  匹配換行在內的所有字元

>>> pattern=r'ghostwu.com'
>>> import re
>>> re.findall( pattern, 'ghostwuacom' )
['ghostwuacom']
>>> re.findall( pattern, 'ghostwubcom' ) 
['ghostwubcom']
>>> re.findall( pattern, 'ghostwu.com' ) 
['ghostwu.com']
>>> re.findall( pattern, 'ghostwu\ncom' ) 
[]
>>> re.findall( pattern, 'ghostwu\ncom', re.S )
['ghostwu\ncom']
>>> 

re.M，多行匹配，主要影響( ^和$ )

>>> str="""
... hi,ghostwu,how are you
... ghostwu: my name is ghostwu,how are you
... ghostwu: nice to meet you
... hello ghostwu
... """
>>> pattern = r"^ghostwu"
>>> re.findall( pattern, str )
[]
>>> re.findall( pattern, str, re.M )
['ghostwu', 'ghostwu']
>>> 

當正則有多行的時候，可以開啟verbose模式re.X

>>> pattern=r"""
... \d{3,4}
... -?
... \d{8}
... """
>>> str="020-88888888"
>>> re.findall( pattern, str )
[]
>>> re.findall( pattern, str, re.X )
['020-88888888']
>>> 

():分組與|  的使用，  假如我們要匹配一個.com,.cn,.net結尾的email

>>> pattern=r"\w+@\w+(.com|.cn|.net)"
>>> email="[email protected]">>> re.match( pattern, email )
<_sre.SRE_Match object at 0x7f2b74481828>
>>> re.match( pattern, '[email protected]' )
<_sre.SRE_Match object at 0x7f2b744818a0>
>>> re.match( pattern, '[email protected]' )
<_sre.SRE_Match object at 0x7f2b74481828>
>>> re.match( pattern, '[email protected]' )
>>> 

匹配超鏈接

>>> html="""
... <a href="http://www.baidu.com">百度</a>
... <a href="index.html">首頁</a>
... <p>這是一段說明</p>
... <a href="http://www.taobao.com">淘寶</a>
... """
>>> re=r"href=\"(.+?)\""
>>> pattern=r"href=\"(.+?)\""
>>> re
'href=\\"(.+?)\\"'
>>> import re
>>> re.findall( pattern, html )
['http://www.baidu.com', 'index.html', 'http://www.taobao.com']
>>>