def sanitize(self, example):
       "Return a copy of example, with non-input attributes replaced by None."
       return [attr_i if i in self.inputs else None
               for i, attr_i in enumerate(example)]
def sanitize(self, example):
       "Return a copy of example, with non-input attributes replaced by None."
       return [attr_i if i in self.inputs else None
               for i, attr_i in enumerate(example)]
Return a copy of example, with non-input attributes replaced by None.