正则表达式 :regular expression
用法:对字符串进行模式匹配
1,对常量字符串(普通字符)进行匹配
import re s = 'pyhton1C#22python1C#5pythonn2C#123' res = re.findall('python',s)#此处'python'就是常量字符串 print(res)
2,对元字符 进行匹配
s = 'pyhton1C#22python1C#5pythonn2C#123' res = re.findall('\d',s) print(res) #['1', '2', '2', '1', '5', '2', '1', '2', '3']