如何仅从python中的文本文件获取基本URL？

Question

I have a text file name weburl which have many urls I want to get only base urls using regex weburls

 wikimapia.org/1649944/Bahawalpur-Railway-Station
 panoramio.com/photo/84118355
 wikimapia.org/1649944/Bahawalpur-Railway-Station
 nativepakistan.com/photos-of-bahawalpur
 defence.pk/threads/pictures-of-pakistan-railways.303027
 nativepakistan.com/photos-of-bahawalpur
 panoramio.com/photo/51311162
 https://hiveminer.com/User/Pakistan Rail Buff

need this

 wikimapia.org
 panoramio.com
 wikimapia.org
 nativepakistan.com
 defence.pk
 nativepakistan.com
 panoramio.com
 https://hiveminer.com

Using regex how can i do it?

Answer 1

One solution could be:

^(?:\w+://)?.*?(?::\d+)?(?=/|$)

It matches begining of line ( ^ ) followed by an optional protocol specification, eg https:// ( (?:\\w+://)? ). Then it matches any number of anything ( .*? ) up to an optional port specification - like :80 ( (?::\\d+)? ). Finally it checks that the match is followed by a / or an end of line $ (the psitive look ahead (?=/|$) ).

Check it out here at regex101 .

Note that if you don't want to match the port part, you could move it in to the positive look ahead. Ie ^(?:\\w+://)?.*?(?=(?::\\d+)?(?:/|$))