import re

from re import findall,search,S

secret_code = 'hadkfalifexxIxxfasdjifja134xxlovexx23345sdfxxyouxx8dfse'

#.的使用，匹配任意字符，换行符除外

a = 'abc123'

b = re.compile('a...')

c = b.findall(a)

print c

#*的使用，匹配前一个字符0次或者多次

a1 = 'abababb123abbbbqjlejl23abbb'

b1 = re.compile('a*b')

c1 = b.findall(a1)

print(c1)

#?的使用，匹配前一个字符0次或者1次

a = 'wqebasd123qewea'

b = re.compile('w?e')

c = b.findall(a)

print(c)

#.*组合使用,贪婪匹配

b = re.compile('xx.*xx')

c = b.findall(secret_code)

print(c)

#.*?组合使用

b = re.compile('xx.*?xx')

c = b.findall(secret_code)

print(c)

#使用括号与不使用括号的差别

b = re.compile('xx(.*?)xx')

c = b.findall(secret_code)

print(c)

输出结果：

['abc1']

['abab', 'abb1', 'abbb', 'abbb']

['e', 'e', 'we']

['xxIxxfasdjifja134xxlovexx23345sdfxxyouxx']

['xxIxx', 'xxlovexx', 'xxyouxx']

['I', 'love', 'you']

import re

#匹配文本中的邮箱

y='123@qq.comaaa@163.combbb@126.comasdfasfs33333@adfcom'

ret = re.findall('\w+@(?:qq|163|126).com',y)

print(ret)

#匹配文本中的时间字符串

time='asfasf1990-07-12asdfAAAbbbb434241'

ret1 = re.search(r'(?P<year>19[09]\d)-(?P<month>\d+)-(?P<days>\d+)',time)

print(ret1.group('year'))

print(ret1.group('month'))

print(ret1.group('days'))

#匹配文本中的所有的身份证数字

a='sfafsf,34234234234,1231313132,154785625475896587,sdefgr54184785ds85,4864465asf86845'

ret2=re.findall('\d{18}',a)

print(ret2)

#匹配出所有整数

a = '1,-3,3,-5,6,7.3,ad,ae,-98'

ret3 = re.compile(r"'(-?\d+)'")

result = ret3.findall(str(re.split(',',a)))

print(result)

输出结果：

['123@qq.com', 'aaa@163.com', 'bbb@126.com']

1990

07

12

['']

['', '-3', '', '-5', '', '-98']