python - Updating regex for extracting IBAN's

Question

I have a regex which extracts German and Austrian IBANs. However, I just realized, that html code sometimes has strange format.

(?:DE|AT)(?:s?[0-9a-zA-Z]){18}(?:(?:s?[0-9a-zA-Z]){2})?

Therefore I have to exclude not valid IBAN matches. In my demo I show examples which show missmatches. How would you exclude this?

question from:https://stackoverflow.com/questions/65830285/updating-regex-for-extracting-ibans

Answer 1

It seems that you only want to match digits. Therefore you can remove a-zA-Z from the character classes. Also note that s could also match a newline, so if you don't want the match to span over newlines, you can match an optional space instead.

(?:DE|AT)(?: ?[0-9]){18}(?:(?: ?[0-9]){2})?

See the updated regex demo