Python正则表达式获取特定模式

Question

['/allstar/NBA-allstar-career-stats.html', '/allstar/NBA_2022.html', '/allstar/NBA_2022.html', '/allstar/NBA_2021.html', '/allstar/NBA_2021.html', '/allstar/NBA_2021_voting.html', '/allstar/NBA_2021.html', '/allstar/NBA_2020.html', '/allstar/NBA_2020.html', '/allstar/NBA_2020_voting.html', '/allstar/NBA_2020.html', '/allstar/NBA_2019.html', '/allstar/NBA_2019.html', '/allstar/NBA_2019_voting.html', '/allstar/NBA_2019.html', '/allstar/NBA_2018.html', '/allstar/NBA_2018.html', '/allstar/NBA_2018_voting.html', '/allstar/NBA_2018.html', '/allstar/NBA_2017.html', '/allstar/NBA_2017.html']

I want to get only /allstar/NBA_2017.html , /allstar/NBA_2018.html , /allstar/NBA_2019.html using re.compile().

Does anyone have an idea?

Answer 1

I'm no expert in regex, but this works.

import re

li = [
    '/allstar/NBA-allstar-career-stats.html', '/allstar/NBA_2022.html',
    '/allstar/NBA_2022.html', '/allstar/NBA_2021.html',
    '/allstar/NBA_2021.html', '/allstar/NBA_2021_voting.html',
    '/allstar/NBA_2021.html', '/allstar/NBA_2020.html',
    '/allstar/NBA_2020.html', '/allstar/NBA_2020_voting.html',
    '/allstar/NBA_2020.html', '/allstar/NBA_2019.html',
    '/allstar/NBA_2019.html', '/allstar/NBA_2019_voting.html',
    '/allstar/NBA_2019.html', '/allstar/NBA_2018.html',
    '/allstar/NBA_2018.html', '/allstar/NBA_2018_voting.html',
    '/allstar/NBA_2018.html', '/allstar/NBA_2017.html',
    '/allstar/NBA_2017.html'
]
prog = r'.*201[789].html'
def match(x):
    return prog.match(x)

prog = re.compile(prog)
res = list(filter(match, li))
print(res)

And this yields the following:

[
    '/allstar/NBA_2019.html', '/allstar/NBA_2019.html',
    '/allstar/NBA_2019.html', '/allstar/NBA_2018.html',
    '/allstar/NBA_2018.html', '/allstar/NBA_2018.html',
    '/allstar/NBA_2017.html', '/allstar/NBA_2017.html'
]

Hope this is what you want!

Answer 2

It's well known that compiling regular expressions in Python is unnecessary unless you have very large numbers of expressions being used in the same program. However, as it seems that you have to compile the expression, you could do this:

li = ['/allstar/NBA-allstar-career-stats.html', '/allstar/NBA_2022.html', '/allstar/NBA_2022.html', '/allstar/NBA_2021.html', '/allstar/NBA_2021.html', '/allstar/NBA_2021_voting.html', '/allstar/NBA_2021.html', '/allstar/NBA_2020.html', '/allstar/NBA_2020.html', '/allstar/NBA_2020_voting.html',
      '/allstar/NBA_2020.html', '/allstar/NBA_2019.html', '/allstar/NBA_2019.html', '/allstar/NBA_2019_voting.html', '/allstar/NBA_2019.html', '/allstar/NBA_2018.html', '/allstar/NBA_2018.html', '/allstar/NBA_2018_voting.html', '/allstar/NBA_2018.html', '/allstar/NBA_2017.html', '/allstar/NBA_2017.html']
m = re.compile('.*NBA_201[789].html')
print(list(set(filter(m.match, li))))