46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
from abc import abstractmethod
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from collections.abc import MutableMapping
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class DefaultMapping(MutableMapping):
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__slots__ = ()
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@abstractmethod
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def __contains__(self, key): # pragma: nocover
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return False
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@abstractmethod
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def __getitem__(self, key): # pragma: nocover
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if hasattr(self.__class__, '__missing__'):
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return self.__class__.__missing__(self, key)
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else:
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raise KeyError(key)
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def get(self, key, default=None):
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if key in self:
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return self[key]
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else:
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return default
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__marker = object()
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def pop(self, key, default=__marker):
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if key in self:
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value = self[key]
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del self[key]
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elif default is self.__marker:
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raise KeyError(key)
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else:
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value = default
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return value
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def setdefault(self, key, default=None):
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if key in self:
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value = self[key]
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else:
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self[key] = value = default
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return value
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DefaultMapping.register(dict)
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