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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 primary_key_tuple(self, item):
 """ Get the primary key tuple from an item """

        if self.range_key is None:
            return (item[self.hash_key.name],)
        else:
            return (item[self.hash_key.name], item[self.range_key.name])