31 lines
1 KiB
Python
31 lines
1 KiB
Python
# Copyright (C) 2014 Andrey Golovizin
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import functools
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def cached_property(fun):
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"""A memoize decorator for class properties."""
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@functools.wraps(fun)
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def get(self):
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try:
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return self._cache[fun]
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except AttributeError:
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self._cache = {}
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except KeyError:
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pass
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ret = self._cache[fun] = fun(self)
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return ret
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return property(get)
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