Regex Subdomain Validation & Input website manual

[rtzki]

Hello,
I have some code like this

import re, urllib

GRUBER_URLINTEXT_PAT = re.compile("(https?://)([^:^/]*)(:\\d*)?(.*)?")

for line in urllib.urlopen("https://pastebin.com/raw/hvGXKp72").readlines():
    print [ str(mgroups[1]).replace('\r\n','') for mgroups in GRUBER_URLINTEXT_PAT.findall(line) ]

this code to read

example.com

only without HTTP,HTTPS & WWW
Now i have a question , how to valid the Subdomain ? e.g

subdomain.example.com

is readable with the code?
and how to input manual the link website from

("https://pastebin.com/raw/hvGXKp72")

? e.g

Please Input Your Website :

then input the website manually.

Thank you in advace,
I hope anybody can help me.

Sorry for my bad english