gistfile1.py

class Vector:
    """
    Demo of a class with multiple signatures for the constructor
    """
    def __init__(self, constructor=()):
        self.values = list(constructor)
    @classmethod
    def from_values(cls, *args):
        return cls(args)
    # There's no real reason to have a separate vector constructor, we could do this:
    def __iter__(self):
        return iter(self.values)
    # otherwise:
    @classmethod
    def from_vector(cls, vector):
        return cls(vector.values)

#------------ end of class definition ---------------------

v = Vector.from_values(1,2,3)
v = Vector([4,5,6])
q = Vector.from_vector(v);