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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def quantity(*args):
 """Create a quantity. This can be from a scalar or vector. Example:: q1 = quantity(1.0, "km/s") q2 = quantity("1km/s") q1 = quantity([1.0,2.0], "km/s") """

    if len(args) == 1:
        if isinstance(args[0], str):
            # use copy constructor to create quantity from string
            return Quantity(from_string(args[0]))
        elif isinstance(args[0], dict):
            if hasattr(args[0]["value"], "__len__"):
                return QuantVec(from_dict_v(args[0]))
            else:
                return Quantity(from_dict(args[0]))
        elif isinstance(args[0], Quantity) or isinstance(args[0], QuantVec):
            return args[0]
        else:
            raise TypeError("Invalid argument type for")
    else:
        if hasattr(args[0], "__len__"):
            return QuantVec(*args)
        else:
            return Quantity(*args)