def _length_up_to_end(self):
        old_ptr = self.tell()
        self.seek(0, end=True)
        new_ptr = self.tell()
        self.seek(old_ptr)
        return old_ptr - new_ptr
dataset/ETHPy150Open samth/pycket/pycket/values.py/W_FileInputPort._length_up_to_end/swapped operands of `-`