regex extract domain from anywhere in string using python

Asked Feb 16 '16 at 11:31

Active Feb 16 '16 at 11:45

Viewed 29 times

How do i match a domain from each of the strings below using python regex. In this case s1 is invalid becaulse .local is not a good valid tld

s1 = '220 Exng-CAS1.aldanube.local Microsoft , 16 Feb 2016 14:52:24 +0400' # ignore this

# catch all this 
s2 = '220 mail6.mithi.com' 
s3 = '220 news-letter.music.jp unknown'
s3 = '220 nice .music.co.uk Welcome to the server. 16 Feb 2016 14:52:24 +0400'

>>> import re
>>> r = re.match('[a-zA-Z0-9\-]+\.', s1)
>>> r.group()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'group'

edited Feb 16 '16 at 11:45

asked Feb 16 '16 at 11:31

Jide Koso

1

Related: [What is the difference between Python's re.search and re.match?](http://stackoverflow.com/questions/180986/what-is-the-difference-between-pythons-re-search-and-re-match) – Wiktor Stribiżew Feb 16 '16 at 11:32
try `r.group()` not `re.group`, aka `r = re.match(r'[a-zA-Z0-9\-]+\.', s1).group()` which further returns none, since `re.match` tries to match from the begining. – Avinash Raj Feb 16 '16 at 11:37
1

You need to compile a list of _good, valid_ TLDs first. – Selcuk Feb 16 '16 at 11:41
@AvinashRaj it is a typo. fixed it – Jide Koso Feb 16 '16 at 11:45
@JideKoso use this `(?<=\.)[a-zA-Z0-9\-]+` regex and check the match against the list of valid domain names. – Avinash Raj Feb 16 '16 at 11:59

regex extract domain from anywhere in string using python

0 Answers0