Regex: How can I catch big numbers with spaces in them?

Question

I'm trying to catch all numbers from a string using Python regex. By numbers I mean integers and floats (using , or .). I managed to get it done using this regex : ([0-9]+[\,|\.][0-9]+|[0-9]+)

But I have a problem, I need it to match big numbers with spaces in them. I mean 20 000 or 5 000 000. And these numbers can be very big with a lot of spaces. I don't know how much. But there will always be 1 space between numbers, no more. For example: 20 30 = this will be 2 differents numbers.

I guess I will need some sort of recursive pattern (?R), but I don't know how to use it.

Can someone help ? :)

Answer 1

You can use a pattern like

(?<!\d)(?<!\d[.,])\d{1,3}(?:\s\d{3})*(?:[,.]\d+)?

See the regex demo.

Details

• (?<!\d)(?<!\d[.,]) - no digit or digit plus a comma or period immediately to the left of the current location are allowed
• \d{1,3} - one, two or three digits
• (?:\s\d{3})* - zero or more sequences of a whitespace and three digits
• (?:[,.]\d+)? - an optional occurrence of a , or . and then one or more digits.

In Python, you can use re.findall:

import re
text = "5 000, 6 123 456,345 and 6 123 456.345... I mean 20 000 or 5 000 000. For example: 20    30"
print( re.findall(r'(?<!\d)(?<!\d[.,])\d{1,3}(?:\s\d{3})*(?:[,.]\d+)?', text) )
## => ['5 000', '6 123 456,345', '6 123 456.345', '20 000', '5 000 000', '20', '30']