How to avoid empty strings in pythong's regular expression function re.findAll?

Question

I use python's re module to recognize integers in a sentence. It produces empty strings as well. Any idea on how to remove those empty strings?

In [15]: myre="[0-9]*"

In [16]: re.findall(myre,"23")
Out[16]: ['23', '']

In [17]: re.findall(myre,"23 is a good number.")
Out[17]:
['23',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '',
 '']

This should answer your question: Make regular expression not match empty string? — mkrieger1
– mkrieger1, Commented Sep 18, 2021 at 12:03

saedx1 · Accepted Answer · 2021-09-18 12:03:54Z

3

You should be using [0-9]+ rather than [0-9]*; the latter matches against 0 or more (meaning that the digits are optional); +, however, matches against one or more.

answered Sep 18, 2021 at 12:03

saedx1

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Bhagyesh Dudhediya · Accepted Answer · 2021-09-18 12:11:08Z

1

The reason is your regex matches 0 or more occurences of digits. Change it to [0-9]+ or \d+ and try out.

answered Sep 18, 2021 at 12:11

Bhagyesh Dudhediya

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