Extract text with special characters using regex python

Question

I have a secuence of emails of the form firstname.lastname@gmail.com .

I would like to get firstname, lastname and domain using regex.

I could manage to get the domain, like this:

domain = re.search('@.+', email).group()

but I'm getting problems with firstname and lastname.

Kindly, can you please explain me how to do it.

Answer 1

You need to use parentheses in regular expressions, in order to access the matched substrings. Notice that there are three parentheses in the regular expression below, for matching the first name, last name and domain, respectively.

m = re.match(r'(.*)\.(.*)@(.*)', email)
assert m is not None
firstname = m.group(1)
lastname = m.group(2)
domain = m.group(3)

Two more notes:

1. You need to escape the dot that separates the first name and the last name, by using a backslash.
2. It is convenient to use the prefix r to the regular expression string, to avoid duplicating the backslash character.

Answer 2

v = "firstname.lastname@gmail.com"
pattern = re.compile(r"(.*)\.(.*)@([a-z]+)\.[a-z]+")
pattern.findall(v)

pattern.findall(v)
Out[7]: [('firstname', 'lastname', 'gmail')]

The output will be a tuple consisting of first name, lastname and domain.

Answer 3

If you want to use 3 capture groups, you can use a negated character class to match all except the characters that you want to allow to prevent some unnecessary backtracking using the .*

^([^\s@.]+)\.([^\s@.]+)@([^\s@]+)$

In parts, the pattern matches:

• ^ Start of string
• ([^\s@.]+) Capture group 1 match 1+ chars other than a whitspace char . or @
• \. Match a dot
• ([^\s@.]+) Capture group 2 match 1+ chars other than a whitspace char . or @
• @ Match an @ char
• ([^\s@]+) Capture group 3 match 1+ chars other than a whitspace char or @
• $ End of string

See a regex demo and a Python demo .

For example:

import re

email = "firstname.lastname@gmail.com";
m = re.match(r'([^\s@.]+)\.([^\s@.]+)@([^\s@]+)$', email)
if m:
    print(m.groups())

Output

('firstname', 'lastname', 'gmail.com')