Python正则表达式

https://docs.python.org/zh-cn/3/library/re.html

https://zhuanlan.zhihu.com/p/68014839

findall,search,sub,S

python findall

import re
str = 'aabbabaabbaa'
print(re.findall('a.b',str))
#['aab', 'aab']

print(re.findall('a*b',str))
#['aab', 'b', 'ab', 'aab', 'b'] *匹配前面的字符0次或者多次

print(re.findall('a.*b',str))
#['aabbabaabb'] .* 贪心算法

print(re.findall('a.*?b',str))
#['aab', 'ab', 'aab'] .*?非贪心算法，遇到开始和结束就截取

print(re.findall('a(.*?)b',str))
#['a', '', 'a'] .*?非贪心算法，只保留括号内的内容


str = '''aabbab
         aabbaa
         bb'''

print(re.findall('a.*?b',str))
#['aab', 'ab', 'aab']

print(re.findall('a.*?b',str,re.S))
#['aab', 'ab', 'aab', 'aa
         b'] re.S不会对
进行中断