//test.py
1 import re
2
3 print (re.search('www', 'www.myweb.com').span())
4 print (re.search('com', 'www.myweb.com').span())
5
6 line = 'Cats are smarter than dogs'
7 #matchObj = re.search(r'(.*) are (.*?) (.*?) (.+)', line, re.M|re.I)
8 #matchObj = re.search(r'(.*) are (.*?) .*', line, re.M|re.I)
9 matchObj = re.search(r'(.*) are (.*) .*', line, re.M|re.I)
10 if matchObj:
11 print 'matchObj.group()', matchObj.group()
12 print 'matchObj.group(1)', matchObj.group(1)
13 print 'matchObj.group(2)', matchObj.group(2)
14 print 'matchObj.groups()', matchObj.groups()
15 else:
16 print 'No match'
17
18 phone = '2017-989-898' # this is one foreign phone number
19 num = re.sub(r'#.*$', '', phone)
20 print 'phone number: ',num
21 num = re.sub(r'\D', '', phone)
22 print "phone number: ", num
23
24 def double(matched):
25 value = int(matched.group('value'))
26 return str(value*2)
27 s = 'A23G4HFD567'
28 print re.sub(r'(?P<value>\d+)', double, s)
//result
# python test.py
(0, 3)
(10, 13)
matchObj.group() Cats are smarter than dogs
matchObj.group(1) Cats
matchObj.group(2) smarter than
matchObj.groups() ('Cats', 'smarter than')
phone number: 2017-989-898
phone number: 2017989898
A46G8HFD1134
Finally:
稍微解释一下：
search 搜索匹配不是必须从字符串开始处匹配，任意位置匹配
span方法是转化匹配对象为原搜索字符串中的位置信息
r'(.*) are (.*) .*'正则表达式的含义：任意字符重复0次到多次，遇到 are，再次任意字符重复0-多次，直至遇到一个任意字符重复0-多次，显然最后的dogs之前会有smart than，如果是条件r'(.*) are (.*?) .*', dog之前重复0-1次，那么就是smart
替换的正则表达，r'#.*$'，从#号开始到结尾，任意重复0-多次
r'\D'，匹配非数字
r'(?P<value>\d+)'，匹配数字1-多次，组取名字value，以double函数做替换项（字符串-》数字-》2倍-》字符串），匹配替换
其实，这个东西，你要用得着时，还是真有用啊！！！