CODEWITHSUNDEEP
pythonregex
Thom Ernst
Thom Ernst

Reputation: 409

Python Regex not returning

I have a function that should return a certain number from a mysql table. The number is filtered out of the string using regex like so: ^\((\d*),\)$. The original string is (36,) and the regex should change it to this: 36. But i still get (36,)!

class db:
    con = mysql.connect()
    cur = con.cursor()

def fo(self, query):
    self.cur.execute(query)
    return re.search('^\((\d*),\)$', 
    str(self.cur.fetchone())).group(0)

and further on I call the function:

return db().fo('SELECT id FROM `GIP-Schema`.user WHERE name = \'{0}\''.format(name))

Upvotes: 3

Views: 65

Answers (2)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626845

You need to get Group 1 contents because ^\((\d*),\)$ pattern matches ( at the start of the string, than captures into Group 1 zero or more digits (I suggest to capture one or more digits), and then matches ,) at the end of the string. Also, it is a good idea to first check if a match was found:

def fo(self, query):
    self.cur.execute(query)
    m = re.search('^\((\d+),\)$', str(self.cur.fetchone()))
    res = ''
    if m:
        res = m.group(1)
    return res

See the regex demo

Upvotes: 3

Thom Ernst
Thom Ernst

Reputation: 409

Thanks to Wiktor for pointing it out, apparently your first group is a 1, not a 0 .group(0) -> .group(1)

Upvotes: 1

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