?模式字符

例如：

 
import re

pattern = r"ice(-)?cream"

if re.match(pattern, "ice-cream"):
   print("Match 1")

if re.match(pattern, "icecream"):
   print("Match 2")

if re.match(pattern, "sausages"):
   print("Match 3")

if re.match(pattern, "ice--ice"):
   print("Match 4")
 

结果

 
>>>
Match 1
Match 2
>>>