Python中re模块的使用

Python的re模块

#预备知识点
#正则表达式regex
#特殊符号和字符 ---> 元字符

正则表达式基础知识
通配符	含义	正则示例	匹配结果
reg1 \| reg2	匹配正则表达式reg1或reg2	foo \| bar	foo
.	匹配任何字符(\n除外)	a.a	abc
^	匹配字符串起始部分	^a	ab....
$	匹配字符串终止部分	.txt$	a.txt
*	匹配0次或者多次前面出现的正则表达式	a*	aaaaa
+	匹配1次或者多次前面出现的正则表达式	[a-z]+	aasx
?	匹配0次或者1次前面出现的正则表达式	first?	first
{N}	匹配N次前面出现的正则表达式	*.c{2}	first.c abc.c
{M,N}	匹配M~N次前面出现的正则表达式	*.c{0,1}	one.c
[...]	匹配来自字符集的任意单个字符	[abc]	b
[...x-y...]	匹配x~y范围中的任意单个字符	[0-9]	9
[^...]	不匹配次字符集中任意单个字符	[^0-9]	a
(*\|+\|?\|{})?	匹配上面频繁出现符号的非贪婪版	(*\|+\|?\|{})?	({})
(...)	匹配封闭的正则表达式，然后另存为子组	([0-1][0-9])?	12
\d	匹配任何十进制数字	\d.txt	1.txt
\w	匹配任何字母数字字符	\w{2}txt	1.txt
\s	匹配任何空格字符	a\sb	a b
\b	匹配任何单词边界	The\bdog	The dog
\N	匹配已保存的子组	([0-9])\1	1
\.	匹配"."这个字符	a\.txt	a.txt

常用正则表达式
正则表达式	描述	匹配结果
\d+(\.\d*)?	任意整数和浮点数	0.004 2 75.
\b[^\Wa-z0-9_][^\WA-Z0-9_]*\b	首字母只能大写	Boo Foo
^http:\/\/([\w-]+(\.[\w-]+)+(\/[\w-.\/\?%&=\u4e00-\u9fa5]*)?)?$	验证网址	http://www.baidu.com/?id=1
^[\u4e00-\u9fa5]{0,}$	验证汉字	汉字汉字
\w+([-+.']\w+)@\w+([-.]\w+)\.\w+([-.]\w+)*	验证电子邮件	example@163.com
^[1-9]([0-9]{16}\|[0-9]{13})[xX0-9]$	验证身份证	14525419951215445X
^13[0-9]{1}[0-9]{8}\|^15[9]{1}[0-9]{8}	验证手机号	138459572***
^(25[0-5]\|2[0-4][0-9]\|[0-1]{1}[0-9]{2}\|[1-9]{1}[0-9]{1}\|[1-9])\.(25[0-5]\|2[0-4][0-9]\|[0-1]{1}[0-9]{2}\|[1-9]{1}[0-9]{1}\|[1-9]\|0)\.(25[0-5]\|2[0-4][0-9]\|[0-1]{1}[0-9]{2}\|[1-9]{1}[0-9]{1}\|[1-9]\|0)\.(25[0-5]\|2[0-4][0-9]\|[0-1]{1}[0-9]{2}\|[1-9]{1}[0-9]{1}\|[0-9])$	验证IP	192.168.1.1
^[a-zA-Z0-9]+([a-zA-Z0-9\-\.]+)?\.s\|)$	验证域名	baidu.com
^([a-zA-Z]\:\|\\)\$[^\\]+\$[^\/:?"<>\|]+\.txt(l)?$	验证文件路径	C:\user\wo
<(.)>(.)<\/(.)>\|<(.)\/>	HTML标签匹配	xxxx

#re模块
#常用的方法
compile(pattern, flags = 0) 　　　　　　匹配任何可选的标记来编译正则表达式的模式，然后返回一个正则表达式对象
match(pattern, string, flags = 0)　　　　使用带有可选标记的正则表达式的模式来匹配字符串。如果匹配成功，返回匹配对象，否则返回None
search(pattern, string ,flags = 0) 　　　　使用可选标记搜索字符串中第一次出现的正则表达式模式。如果匹配成功，则返回匹配对象，否则返回None
findall(pattern, string[,flags] ) 　　　　    查找字符串中所有(非重复)出现的正则表达式模式，并返回一个匹配列表
finditer(pattern, string[,flags] ) 　　　　   与findall()相同，但返回的是一个迭代器。对于每一次匹配，迭代器都能返回一个匹配对象
split(pattern, string, max = 0) 　　　　根据正则表达式的模式分隔符，split函数将字符串分割为列表，返回匹配列表，分割最多操作max次
group(num = 0) 　　　　　　　　  　　返回整个匹配对象，或者编号为num的特定子组

import re

m = re.search('foo','asdasdfooasd')

#这里如果使用match将匹配不到任何字符串，因为match从第一个a开始匹配

if m is not None:

    print(m.group())

regex = <(.*)>(.*)<\/(.*)>|<(.*)\/>

m = re.search(regex,"aa<a>aaaa</a>")

#一样只有search能匹配到标签

if m is not None:

    print(m.group())

regex = '(foo\w)(\w)'

m = re.match(r'(foo\w)(\w)','fooasdfooasd')

if m is not None:

    print(m.group(1))

    print(m.groups())

#输出

#fooa

#('fooa', 's')

regex = 'apple'

m = re.findall(regex,'apple1 apple2 apple3')

    print(m)

#输出

#['apple', 'apple', 'apple']

regex = 'apple'

m = [ g.group() for g in re.finditer(regex,'apple1 apple2 apple3')]

print(m)

#输出

#['apple', 'apple', 'apple']

list = [

'aaa, bbb ccc',

'ddd, eee fff',

]

for i in list:

    print(re.split(', |(?= (?:[a-z]{3})) ',i))

#输出

#['aaa', 'bbb', 'ccc']

#['ddd', 'eee', 'fff']

re模块小实例：

__author__ = 'cq'

import  re

from random import randrange,choice,randint

from string import ascii_lowercase as lc

from time import ctime

#生成数据文件

def generate_data():

    with open('./data.txt','w') as f:

        for i in range(randint(20,30)):

            tlds = ('com', 'edu', 'net', 'org', 'gov')

            dtint = randint(100000000,1200000000) #生成时间戳

            dtstr = ctime(dtint)  #将时间戳转化为特定时间格式

            llen = randrange(4, 8) #用户名长度

            login = ''.join(choice(lc) for i in range(llen))  #生成用户名

            dlen = randrange(llen,13)                         #域名长度

            dom = ''.join(choice(lc) for i in range(dlen))    #生成域名

            data_line = "%s::%s@%s.%s::%d-%d-%d\n" % (dtstr, login, dom, choice(tlds), dtint, llen, dlen)

            f.write(data_line) #写入文件

            print(data_line)   #打印每行记录

#匹配指定日期的行

def match_date():

    regex = '(Mon|Tue|Wed|Thu|Fri|Sat|Sun)(.*)'

    with open('./data.txt','r') as f:

        m = re.findall(regex,f.read())

        for i in m:

            print(i)

#匹配在某时间段内的记录

def match_time_slot():

    regex = ' ([0-9]{1,2}) .*([0-9]{4})::(.*)'

    # regex = ' ([0-9]{0,2}).*(::)(.*) '

    with open('./data.txt','r') as f:

        m = re.findall(regex,f.read())

        for i in m:

            if 2000 <= int(i[1]) and int(i[1]) <= 2020 and 20 <= int(i[0]) and int(i[0]) <= 31:

                print(i)

#匹配某名单中人员的记录

def match_name():

    regex = '::([a-z]{2,13})@([a-z]{2,13})\.(com|edu|net|org|gov)'

    with open('./data.txt','r') as f:

        m = re.findall(regex,f.read())

        for i in m:

            print(i)

def main():

    generate_data()

    print("\n---------------match_date--------------------\n")

    match_date()

    print("\n---------------match_time_slot--------------------\n")

    match_time_slot()

    print("\n---------------match_name--------------------\n")

    match_name()

if '__main__' == __name__:

    main()

输出结果

Sun Mar  5 00:55:55 1989::qvnc@ygeowwaf.com::605033755-4-8

Mon Oct 17 17:16:31 2005::yene@rtewqvvyfe.edu::1129540591-4-10

Tue Oct  7 06:33:30 2003::wlyi@coagmnososzy.edu::1065479610-4-12

Mon Oct 16 00:01:06 2006::zsgok@jkpiplcm.edu::1160928066-5-8

Wed Mar 15 06:37:35 2000::paok@anpekysphicu.com::953073455-4-12

Wed Mar 26 12:27:25 1980::bodqoe@iydohek.org::322892845-6-7

Mon Jun  5 13:54:28 1989::fgiy@oppcjnafx.gov::613029268-4-9

Sun Jul 25 05:27:23 2004::agmljfx@qvxgjqtkiwnl.org::1090704443-7-12

Mon Nov 14 16:15:36 2005::tctz@bcikib.gov::1131956136-4-6

Sun Jan 14 23:20:42 2007::qqlfkf@isslbh.com::1168788042-6-6

Sun Jul 27 02:00:13 1980::cpiqwau@drbpfsfglip.edu::333482413-7-11

Sun Feb 20 16:10:34 2005::aguqfd@hnrcaged.com::1108887034-6-8

Wed Jun 27 06:13:05 1979::kowyk@ruoackjavkpq.net::299283185-5-12

Wed Oct 12 19:52:54 1994::kqaol@mzewoas.edu::781962774-5-7

Thu Aug 23 01:46:59 1973::uofpdq@zdeidbobin.org::114889619-6-10

Sat Dec 21 11:36:20 1991::hodw@wfbw.org::693286580-4-4

Tue Jun 22 14:42:19 1993::azgagm@nfmguh.org::740731339-6-6

Sun Feb 23 04:50:57 2003::cysfu@fnzdo.com::1045947057-5-5

Fri Jun 10 13:38:02 1983::qdhqw@fcdsvlmnhx.net::424071482-5-10

Sat Jan 24 21:56:37 1998::dfyicjw@fklbymd.org::885650197-7-7

Sun Jun  3 07:48:45 2007::wptuyjk@tsngnle.edu::1180828125-7-7

Mon Nov 19 00:34:41 2001::ocjlb@nusyk.net::1006101281-5-5

Sat Dec  1 21:01:23 1973::bvhx@lmir.net::123598883-4-4

Sun Dec 16 17:42:51 1979::rpgs@hppau.org::314185371-4-5

Mon Jul 21 23:46:13 1986::fnsro@nmbcwdmie.org::522344773-5-9

---------------match_date--------------------

('Sun', ' Mar  5 00:55:55 1989::qvnc@ygeowwaf.com::605033755-4-8')

('Mon', ' Oct 17 17:16:31 2005::yene@rtewqvvyfe.edu::1129540591-4-10')

('Tue', ' Oct  7 06:33:30 2003::wlyi@coagmnososzy.edu::1065479610-4-12')

('Mon', ' Oct 16 00:01:06 2006::zsgok@jkpiplcm.edu::1160928066-5-8')

('Wed', ' Mar 15 06:37:35 2000::paok@anpekysphicu.com::953073455-4-12')

('Wed', ' Mar 26 12:27:25 1980::bodqoe@iydohek.org::322892845-6-7')

('Mon', ' Jun  5 13:54:28 1989::fgiy@oppcjnafx.gov::613029268-4-9')

('Sun', ' Jul 25 05:27:23 2004::agmljfx@qvxgjqtkiwnl.org::1090704443-7-12')

('Mon', ' Nov 14 16:15:36 2005::tctz@bcikib.gov::1131956136-4-6')

('Sun', ' Jan 14 23:20:42 2007::qqlfkf@isslbh.com::1168788042-6-6')

('Sun', ' Jul 27 02:00:13 1980::cpiqwau@drbpfsfglip.edu::333482413-7-11')

('Sun', ' Feb 20 16:10:34 2005::aguqfd@hnrcaged.com::1108887034-6-8')

('Wed', ' Jun 27 06:13:05 1979::kowyk@ruoackjavkpq.net::299283185-5-12')

('Wed', ' Oct 12 19:52:54 1994::kqaol@mzewoas.edu::781962774-5-7')

('Thu', ' Aug 23 01:46:59 1973::uofpdq@zdeidbobin.org::114889619-6-10')

('Sat', ' Dec 21 11:36:20 1991::hodw@wfbw.org::693286580-4-4')

('Tue', ' Jun 22 14:42:19 1993::azgagm@nfmguh.org::740731339-6-6')

('Sun', ' Feb 23 04:50:57 2003::cysfu@fnzdo.com::1045947057-5-5')

('Fri', ' Jun 10 13:38:02 1983::qdhqw@fcdsvlmnhx.net::424071482-5-10')

('Sat', ' Jan 24 21:56:37 1998::dfyicjw@fklbymd.org::885650197-7-7')

('Sun', ' Jun  3 07:48:45 2007::wptuyjk@tsngnle.edu::1180828125-7-7')

('Mon', ' Nov 19 00:34:41 2001::ocjlb@nusyk.net::1006101281-5-5')

('Sat', ' Dec  1 21:01:23 1973::bvhx@lmir.net::123598883-4-4')

('Sun', ' Dec 16 17:42:51 1979::rpgs@hppau.org::314185371-4-5')

('Mon', ' Jul 21 23:46:13 1986::fnsro@nmbcwdmie.org::522344773-5-9')

---------------match_time_slot--------------------

('', '', 'agmljfx@qvxgjqtkiwnl.org::1090704443-7-12')

('', '', 'aguqfd@hnrcaged.com::1108887034-6-8')

('', '', 'cysfu@fnzdo.com::1045947057-5-5')

---------------match_name--------------------

('qvnc', 'ygeowwaf', 'com')

('yene', 'rtewqvvyfe', 'edu')

('wlyi', 'coagmnososzy', 'edu')

('zsgok', 'jkpiplcm', 'edu')

('paok', 'anpekysphicu', 'com')

('bodqoe', 'iydohek', 'org')

('fgiy', 'oppcjnafx', 'gov')

('agmljfx', 'qvxgjqtkiwnl', 'org')

('tctz', 'bcikib', 'gov')

('qqlfkf', 'isslbh', 'com')

('cpiqwau', 'drbpfsfglip', 'edu')

('aguqfd', 'hnrcaged', 'com')

('kowyk', 'ruoackjavkpq', 'net')

('kqaol', 'mzewoas', 'edu')

('uofpdq', 'zdeidbobin', 'org')

('hodw', 'wfbw', 'org')

('azgagm', 'nfmguh', 'org')

('cysfu', 'fnzdo', 'com')

('qdhqw', 'fcdsvlmnhx', 'net')

('dfyicjw', 'fklbymd', 'org')

('wptuyjk', 'tsngnle', 'edu')

('ocjlb', 'nusyk', 'net')

('bvhx', 'lmir', 'net')

('rpgs', 'hppau', 'org')

('fnsro', 'nmbcwdmie', 'org')

Process finished with exit code 0

巴特西

Python中re模块的使用

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