1、匹配一行文字中的所有开头的字母内容
#coding=utf-8
import re
s="i love you not because of who you are, but because of who i am when i am with you"
content=re.findall(r"\b\w",s)
print content
c:\Python27\Scripts>python task_test.py
['i', 'l', 'y', 'n', 'b', 'o', 'w', 'y', 'a', 'b', 'b', 'o', 'w', 'i', 'a', 'w', 'i', 'a', 'w', 'y']
2、匹配一行文字中的所有开头的数字内容
import re
s="i love you not because 12sd 34er 56df e4 54434"
content=re.findall(r"\b\d",s)
print content
c:\Python27\Scripts>python task_test.py
['1', '3', '5', '5']
3、匹配一行文字中的所有开头的数字内容或数字内容
>>> print re.match(r"\w+","123sdf").group()
123sdf
4、 只匹配包含字母和数字的行
#coding=utf-8
import re
s="i love you not because\n12sd 34er 56\ndf e4 54434"
content=re.findall(r"\w+",s,re.M)
print content
c:\Python27\Scripts>python task_test.py
['i', 'love', 'you', 'not', 'because', '12sd', '34er', '56', 'df', 'e4', '54434']
5、写一个正则表达式，使其能同时识别下面所有的字符串：'bat', 'bit', 'but', 'hat', 'hit', 'hut‘
import re
s="'bat', 'bit', 'but', 'hat', 'hit', 'hut"
content=re.findall(r"..t",s)
print content
c:\Python27\Scripts>python task_test.py
['bat', 'bit', 'but', 'hat', 'hit', 'hut']
6、匹配所有合法的python标识符
#coding=utf-8
import re
s="awoeur awier !@# @#4_-asdf3$^&()+?><dfg$\n$"
content=re.findall(r".*",s,re.DOTALL)
print s
print content
c:\Python27\Scripts>python task_test.py
awoeur awier !@# @#4_-asdf3$^&()+?><dfg$
$
['awoeur awier !@# @#4_-asdf3$^&()+?><dfg$\n$', '']
7、提取每行中完整的年月日和时间字段
#coding=utf-8
import re
s="""se234 1987-02-09 07:30:00
1987-02-10 07:25:00"""
content=re.findall(r"\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}",s,re.M)
print s
print content
c:\Python27\Scripts>python task_test.py
se234 1987-02-09 07:30:00
1987-02-10 07:25:00
['1987-02-09 07:30:00', '1987-02-10 07:25:00']
8、将每行中的电子邮件地址替换为你自己的电子邮件地址
#coding=utf-8
import re
s="""[email protected], [email protected], [email protected]
[email protected], [email protected]
content=re.sub(r"\w+@\w+.com","[email protected]",s)
print s
print "_______________________________________"
print content
c:\Python27\Scripts>python task_test.py
[email protected], [email protected], [email protected]
[email protected], [email protected]
_______________________________________
[email protected], [email protected], [email protected]
[email protected], [email protected]
9、匹配\home关键字：
>>> re.findall(r"\\home","skjdfoijower \home \homewer")
['\\home', '\\home']
1、使用正则提取出字符串中的单词
#coding=utf-8
import re
s="""i love you not because of who 234 you are, 234 but 3234ser because of who i am when i am with you"""
content=re.findall(r"\b[a-zA-Z]+\b",s)
print content
c:\Python27\Scripts>python task_test.py
['i', 'love', 'you', 'not', 'because', 'of', 'who', 'you', 'are', 'but', 'because', 'of', 'who', 'i', 'am', 'when', 'i', 'am', 'with', 'you']
2、使用正则表达式匹配合法的邮件地址：
import re
s="""[email protected], [email protected] [email protected] [email protected] [email protected] saldkfj.com [email protected]"""
content=re.findall(r"\w+@\w+.com",s)
print content
c:\Python27\Scripts>python task_test.py
['[email protected]', '[email protected]', '[email protected]', '[email protected]']