Python: extracting numbers from string using regex

Question

I'm having a string and trying to find all numbers such as 1, -1.5, .5, etc. I already found this question with very helpful answers. The only problem I have is that all these solution seem to match "too much". For example, the match "17" in "MH17". How can I extend any of the proposed solution so that a number cannot start with (or contain) a letter?

Can you provide valid and invalid cases of matching and what have you tried? — hwnd, Aug 07 '14 at 02:19

score 2 · Accepted Answer · answered Aug 07 '14 at 02:36

2

I rewrite the original regex: fix +/- bug and exclude the case starting with letter

(?<=\s)[+-]?\d+(?:.\d)?\d*

Also please find the demo

answered Aug 07 '14 at 02:36

HMK

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+1, but you can simplify it a bit with `(?<=\s)[+-]?\d+(?:.\d+)?` – The Guy with The Hat Aug 07 '14 at 02:40
2

Shouldn't you escape the dot? – hwnd Aug 07 '14 at 02:41
@TheGuywithTheHat Thank you very much for the improvement. – HMK Aug 07 '14 at 02:43
Thanks a lot! This works pretty perfect for my needs! – Christian Aug 07 '14 at 05:09

Python: extracting numbers from string using regex

1 Answers1