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""" |
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A subclass of MutableAttr that has defaultdict support. |
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""" |
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try: |
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from collections.abc import Mapping |
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except ImportError: |
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from collections import Mapping |
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import six |
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|
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from attrdict.mixins import MutableAttr |
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__all__ = ['AttrDefault'] |
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class AttrDefault(MutableAttr): |
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""" |
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An implementation of MutableAttr with defaultdict support |
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""" |
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def __init__(self, default_factory=None, items=None, sequence_type=tuple, |
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pass_key=False): |
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if items is None: |
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items = {} |
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elif not isinstance(items, Mapping): |
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items = dict(items) |
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self._setattr('_default_factory', default_factory) |
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self._setattr('_mapping', items) |
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self._setattr('_sequence_type', sequence_type) |
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self._setattr('_pass_key', pass_key) |
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self._setattr('_allow_invalid_attributes', False) |
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def _configuration(self): |
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""" |
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The configuration for a AttrDefault instance |
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""" |
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return self._sequence_type, self._default_factory, self._pass_key |
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def __getitem__(self, key): |
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""" |
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Access a value associated with a key. |
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Note: values returned will not be wrapped, even if recursive |
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is True. |
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""" |
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if key in self._mapping: |
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return self._mapping[key] |
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elif self._default_factory is not None: |
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return self.__missing__(key) |
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raise KeyError(key) |
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def __setitem__(self, key, value): |
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""" |
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Add a key-value pair to the instance. |
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""" |
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self._mapping[key] = value |
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def __delitem__(self, key): |
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""" |
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|
Delete a key-value pair |
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""" |
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del self._mapping[key] |
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def __len__(self): |
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""" |
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Check the length of the mapping. |
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""" |
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return len(self._mapping) |
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def __iter__(self): |
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""" |
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|
Iterated through the keys. |
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""" |
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return iter(self._mapping) |
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def __missing__(self, key): |
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""" |
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|
Add a missing element. |
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""" |
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if self._pass_key: |
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self[key] = value = self._default_factory(key) |
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else: |
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self[key] = value = self._default_factory() |
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return value |
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def __repr__(self): |
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""" |
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|
Return a string representation of the object. |
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""" |
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return six.u( |
|
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"AttrDefault({default_factory}, {pass_key}, {mapping})" |
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).format( |
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default_factory=repr(self._default_factory), |
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pass_key=repr(self._pass_key), |
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mapping=repr(self._mapping), |
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) |
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def __getstate__(self): |
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""" |
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|
Serialize the object. |
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|
""" |
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return ( |
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self._default_factory, |
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self._mapping, |
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self._sequence_type, |
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self._pass_key, |
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self._allow_invalid_attributes, |
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) |
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def __setstate__(self, state): |
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""" |
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|
Deserialize the object. |
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""" |
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(default_factory, mapping, sequence_type, pass_key, |
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allow_invalid_attributes) = state |
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|
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self._setattr('_default_factory', default_factory) |
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self._setattr('_mapping', mapping) |
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self._setattr('_sequence_type', sequence_type) |
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self._setattr('_pass_key', pass_key) |
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|
self._setattr('_allow_invalid_attributes', allow_invalid_attributes) |
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|
|
|
@classmethod |
|
|
def _constructor(cls, mapping, configuration): |
|
|
""" |
|
|
A standardized constructor. |
|
|
""" |
|
|
sequence_type, default_factory, pass_key = configuration |
|
|
return cls(default_factory, mapping, sequence_type=sequence_type, |
|
|
pass_key=pass_key) |
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|
