Precondition "Mixed words (letters and digits combined) are not allowed." is not satisfied. Something like this: pattern = re.compile('[a-z][\d]', re.IGNORECASE) assert pattern.findall(words) == [] More

For the precondition: In my solution, suppose **words = "Hello1 World 4hello"**, then **pattern.findall(words)** outputs **['o1']**. This is fine as long as digits-after-letters pattern is found. What about its reverse? What should I do to also include **4hello** word types? I can't seem to w More