Regex not able to identify emails with special characters? - regex

Question

Problem:
I wrote a regex to identify email addresses in the text.But it is not recognizing the emails with special character like -.So I modified the regex to match emails with special characters.Now it is not matching normal email.s
regex = r"\"?([-a-zA-Z0-9.`?{}]+#\w+\.\w+)\"?"
TEXT = "To address parsed is bilgi "
DETECT = "bilgi#kleintoys.com"
NOT_DETECT = "bilgi#klei-ntoys.com"
Modified:
regex = r"\"?([-a-zA-Z0-9.`?{}]+#\w+\-+\w+\.\w+)\"?"
TEXT = "To address parsed is bilgi "
DETECT = "bilgi#klei-ntoys.com"
NOT_DETECT = "bilgi#kleintoys.com"
Is there any regex combining both these two regex to match both emails.
like
bilgi#klei-ntoys.com
bilgi#kleintoys.com

Answer 1

You could make a much more loose regex.
Here is a proposition that does match both addresses:
[a-zA-Z\d]+#.+\..{,3}
Let's break it down:
[a-zA-Z\d]+#.+\.[a-zA-Z\d]{,3}
[a-zA-Z\d] Match any alphanumerical character...
+ ... at least once
# Match the arobase
.+ Match any character at least once...
\. ... before a dot
[a-zA-Z\d]{,3} Then check at least three alphanumerical characters
Checking with Python:
>>> import re
>>> s = "bilgi#kle-intoys.com"
>>> re.match("[a-zA-Z\d]+#.+\.[a-zA-Z\d]{,3}", s)
<_sre.SRE_Match object; span=(0, 20), match='bilgi#kle-intoys.com'>
>>> s = "bilgi#kleintoys.com"
>>> re.match("[a-zA-Z\d]+#.+\.[a-zA-Z\d]{,3}", s)
<_sre.SRE_Match object; span=(0, 19), match='bilgi#kleintoys.com'>

Answer 2

To make your pattern work, you need to add a part that will match 0+ sequences of - and then 1 or more word chars, (?:-\w+)*:
"?([-a-zA-Z0-9.`?{}]+#\w+(?:-\w+)*\.\w+)"?
^^^^^^^^^
See the regex demo.
Details
"? - an optional "
([-a-zA-Z0-9.`?{}]+#\w+(?:-\w+)*.\w+) - Group 1 (what re.findall will output):
[-a-zA-Z0-9.`?{}]+ - 1 or more chars defined in the character class (-, ASCII letters, digits, ., `, ?, {, } (note you might want to restrict this part to start with any letter and then also match _, like [^\W\d_][-\w.`?{}]*)
# - a #
\w+ - 1 or more letters/digits/_
(?:-\w+)* - 0+ sequences of - and then 1 or more letters/digits/_
\. - a dot
\w+ - 1 or more letters/digits/_
"? - an optional "
Python demo:
import re
rx = r"\"?([-a-zA-Z0-9.`?{}]+#\w+(?:-\w+)*\.\w+)\"?"
s = """ "bilgi#kleintoys.com" and bilgi#klei-ntoys.com"""
print(re.findall(rx, s))
# => ['bilgi#kleintoys.com', 'bilgi#klei-ntoys.com']

Answer 3

Use * instead of +:
r"\"?([-a-zA-Z0-9.`?{}]+#\w+\-*\w+\.\w+)\"?"
A star after the hyphen matches zero or more occurrences. You have a plus which matches at least one hyphen. BTW, instead of \-* you may use [-]*. Between the square brackets any other special characters, besides -, can be inserted.