CODEWITHSUNDEEP
pythonrecursion
codyc4321
codyc4321

Reputation: 9672

recursive function returns itself without being asked to

I have a prompt in terminal that is calling itself without being asked to. The behavior in question is if it is fed names like ['artist', 'art', 'dogs'], and the match matches 1 of them, when it reaches elif len(matches) == 1:, it will ask you to confirm "Is dogs OK?" twice. It always asks twice, then correctly returns 'dogs'

def hostfunc(names):

    def _prompt(answer=None):
        if answer == None:
            answer = gather("Pick from {names}...if you want more than 1, separate like \"name1, name2\"".format(names=names))
            _prompt(answer=answer)
        matches = check_for_answer_matches(names, answer)
        matches_string = process_matches(matches)
        if len(matches) == 0:
            answer = gather("That string didn't match any of {names}, please try again".format(names=names))
            _prompt(answer=answer)
        elif len(matches) == 1:
            answer = gather("Is {matches_string} OK? ('y' or 'n' to restart)".format(matches_string=matches_string))
            if answer == 'y':
                return matches
            elif answer == 'n':
                return _prompt()
            return matches
        elif len(matches) > 1:
            answer = gather("That string matched {matches_string}, is that OK? ('y' or 'n' to restart)".format(matches_string=matches_string))
            if answer == 'y':
                return matches
            elif answer == 'n':
                return _prompt()

    return _prompt()

I've been stuck on it all day because as I see it, the hostfunc tries to return prompt which sees it has no answer, and asks you to "Pick from...", which calls _prompt with the answer. _prompt sees it has an answer, gets the matches, and since len(matches) == 1, it should ask you if "Is dogs OK?" then immediately return ['dogs'] when you say 'y'.

I also tried doing x = _prompt() and then returning x instead. Why does this thing ask you to confirm twice? Thank you

Upvotes: 0

Views: 54

Answers (1)

Syntactic Fructose
Syntactic Fructose

Reputation: 20076

It seems your if answer == None is not returning after calling _prompt again, so you'll iterate with the correct answer variable twice

so you'll call _prompt() with answer=None, which will prompt input and then call _prompt(answer), which will find the correct matches. but once that _prompt(answer) call is finished, it will resume with the callee which now has answer set accordingly, making it technically run the final answer twice.

changing _prompt(answer) to return _prompt(answer) should fix this

Upvotes: 1

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