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Python

Gilbert Craig
Gilbert Craig
2,102 Points
Posted by Gilbert Craig
Gilbert Craig
2,102 Points

Classmethod contruction challenge - stumped

I am definitely stuck with this one ..... Any pointer greatly appreciated 

    @classmethod
    def from_string(cls, string):
        answer = []
        for char in string:
            if char == 'dot':
                answer.append('.')
            elif char == 'dash':
                answer.append('_')
        return cls('-'.join(answer))

1 Answer

Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 27,510 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 27,510 Points

You are very close! I can see you understood the concept pretty well.

I fixed the code and commented the lines where changes should take place.

Think of 'dot' and 'dash' as tokens in a string where tokens are separated by hyphens rather than thinking of the string in terms of a string iterable.

So... we create a LIST called tokens, which we split on the hyphens '-'... then your code will work. Also, the question wanted a LIST to be returned -- you built the list correctly as 'answer' -- so rather than joining it again to be a single string, just return the list.

Good luck with Python, it is worth the effort!

    @classmethod
    def from_string(cls, string):
        answer = []
        tokens = string.split('-')  # ADD THIS
        for char in tokens: # CHANGE ITERABLE to TOKENS LIST
            if char == 'dot':
                answer.append('.')
            elif char == 'dash':
                answer.append('_')
        return cls(answer) # RETURN THE LIST ANSWER RATHER THAN JOINING
Gilbert Craig
Gilbert Craig
2,102 Points
Gilbert Craig
Gilbert Craig
2,102 Points

Thanks Jeff for the comprehensive answer