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Python

Posted by Katherina Kallis
Katherina Kallis
3,385 Points

Morse.py : class method incorrect

Task: Let's practice using @classmethod!
Create a class method in Letter named from_string that takes a string like "dash-dot" and creates an instance with the correct pattern (['_', '.']).

My question:
I don't see my error. As far as I can see, I used my decorator, passed cls as argument, looped over the correct list and returned the correct pattern list.

morse.py 
class Letter:
    def __init__(self, pattern=None):
        self.pattern = pattern

    def __iter__(self):
        yield from self.pattern

    def __str__(self):
        output = []
        for blip in self:
            if blip == '.':
                output.append('dot')
            else:
                output.append('dash')
        return '-'.join(output)

    @classmethod
    def from_string(cls, patternstring):
        splitted_list = patternstring.split"-"
        pattern_list = []
        for blip in splitted_list:
            if blip == 'dot':
                pattern_list.append('.')
            else:
                pattern_list.append('_')
        return cls(pattern_list)


class S(Letter):
    def __init__(self):
         pattern = ['.', '.', '.']
         super().__init__(pattern)
Katherina Kallis
Katherina Kallis
3,385 Points

I solved it! I had to iterate over a copy of a copy of the splitted_list

1 Answer

Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

Very close! But when calling a method (like "split"), the name must be followed by parentheses. Any arguments to be passed go inside the parentheses:

        splitted_list = patternstring.split("-")