Second approach use regex

check_numbers2.py

# this is a test string with numbers to be found
test_text = "this is a string with one number and then twenty thousand numbers and three thousand thirty four and three thousand five hundred forty five numbers"
# firstly we could think of a simple regex to match numbers
regex = r"\b(three thousand five hundred forty five|three thousand thirty four|twenty thousand|three thousand|forty five|thirty four|twenty|five|four|three|two|one)\b"
re.findall(regex, test_text)
# the result is not we were expecting 

# recalibrate the order from "rare" numbers to "frequent" ones
regex = r"\b(three thousand five hundred forty five|three thousand thirty four|twenty thousand|three thousand|forty five|thirty four|twenty|five|four|three|two|one)\b"
re.findall(regex, test_text)

# better result, we got what expected, can we do even better?