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Python

Diego Salas Polar
Diego Salas Polar
21,431 Points
Posted by Diego Salas Polar
Diego Salas Polar
21,431 Points

No method named `from_string`

I don't know what to do. Please help me.

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(self, x):
        some_list = x.split('-')
        for i in some_list:
            if i == 'dash':
                self.pattern.append('_')
            else:
                self.pattern.append('.')
        return self.pattern


class S(Letter):
    def __init__(self):
         pattern = ['.', '.', '.']
         super().__init__(pattern)

2 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,426 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,426 Points

As Christopher Shaw, said you cannot append to a string, plus in a classmethod, there is not instance so attribute self.pattern does not exist.

  • Instead, create a new list, such as pattern = [], then append to this pattern list.
  • The return value should be an new instance created with the newly created pattern. This can be done using self(pattern)

Note: the first argument in a classmethod can be called almost anything. However, the convention is to use cls instead of "self". This helps set classmethod apart from instance methods.

Post back if you need more help. Good luck!!