Python – How to extract numbers from a string in Python

numberspythonregexstring

I would like to extract all the numbers contained in a string. Which is better suited for the purpose, regular expressions or the isdigit() method?

Example:

line = "hello 12 hi 89"

Result:

[12, 89]

Best Answer

If you only want to extract only positive integers, try the following:

>>> txt = "h3110 23 cat 444.4 rabbit 11 2 dog"
>>> [int(s) for s in txt.split() if s.isdigit()]
[23, 11, 2]

I would argue that this is better than the regex example because you don't need another module and it's more readable because you don't need to parse (and learn) the regex mini-language.

This will not recognize floats, negative integers, or integers in hexadecimal format. If you can't accept these limitations, jmnas's answer below will do the trick.