Question

I’m pretty sure I’m missing something very elementary here as I’m normally ok with Python & Regex. I’m looking to see if the string supplied contains at least one number, and this is the command line I’m going through, but always getting false…

>>> import re
>>> test_string = "123567890"
>>> pat = re.compile("[0-9]")
>>> pat.search(test_string) == True
False

Before posting this I’ve tried a few other permutations and not getting very far, what am I doing wrong?

Answer 1

pat.search doesn’t return a Boolean value but a MatchObject so your comparison will fail:

In [9]: p = pat.search(test_string)

In [10]: p
Out[10]: <_sre.SRE_Match at 0x3cfa608>

In [11]: type(p)
Out[11]: _sre.SRE_Match

See re.search docs:

re.search(pattern, string, flags=0)

Scan through string looking for a location where the regular
expression pattern produces a match, and return a corresponding
MatchObject instance. Return None if no position in the string matches
the pattern; note that this is different from finding a zero-length
match at some point in the string.