正则表达式的简化？

r2

r1

re.compile

# -*- coding: utf-8 -*-



import itertools

import re



string = "".join(map(str, range(1000000)))



r1 = r"[13579]{3}"

r2 = rf'{"|".join(map("".join, itertools.product("13579", repeat=3)))}'



r1 = re.compile(r1)

r2 = re.compile(r2)



match1 = re.findall(r1, string)

match2 = re.findall(r2, string)



assert sorted(match1) == sorted(match2)

In [78]: %timeit re.findall(r1, string)

167 ms ± 520 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)



In [79]: %timeit re.findall(r2, string)

1.08 s ± 2.69 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)