def __del__(self):
        self.close()
Subtract count, but keep only results with positive counts.
dataset/ETHPy150Open okfn/ofs/ofs/local/zipstore.py/ZOFS.__del__--crossover with--dataset/ETHPy150Open PythonCharmers/python-future/docs/3rd-party-py3k-compat-code/pandas_py3k.py/_Counter.__sub__