To find those parts of a string which match a pattern specified using a Regular Expression, the following code is probably the simplest.
import re source = "A string 123 with numbers 456 and letters 789" pattern = "[0-9]+" results = re.findall(pattern, source) for match in results: print(match)
Result:
123 456 789
All matches of the regex inside the source string will be stored in the results list.