re.match

re.match方法只是进行匹配，如果完全相同才返回，否则直接返回None

import re

print(re.match("123","321"))

print(re.match("123","132"))

print(re.match("123","12"))

print(re.match("123","123"))

print(re.match("123","123").group())

None
None
None
<_sre.SRE_Match object; span=(0, 3), match='123'>
123