Morse Code Challenge

my outout seems correct..I got dot-dot-dot. Why does it say it's wrong?

from question: "...I've included an S class as an example (I'll generate the others when I test your code) and it's str output should be "dot-dot-dot"...."

message: Bummer: Didn't get the right string output. Got: dot-dot-dot for S()

code: class Letter: def init(self, pattern=None): self.pattern = pattern def str(self): test=[] for x in self.pattern: if x == ".": test.append("dot") elif x == "-": test.append("dash") return "-".join(test)

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

class Letter:
    def __init__(self, pattern=None):
        self.pattern = pattern
    def __str__(self):
        test=[]
        for x in self.pattern:
            if x == ".":
                test.append("dot")
            elif x == "-":
                test.append("dash")
        return "-".join(test)

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