|
1 | | -from copy import deepcopy |
2 | | - |
3 | | - |
4 | | -def immutable(self, *args, **kwargs): |
5 | | - r""" |
6 | | - Function for not implemented method since the object is immutable |
7 | | - """ |
8 | | - |
9 | | - raise AttributeError( |
10 | | - f"'{self.__class__.__name__}' object is read-only" |
11 | | - ) |
12 | | - |
13 | | - |
14 | | -_empty_frozendict = None |
15 | | - |
16 | | - |
17 | | -class frozendict(dict): |
18 | | - r""" |
19 | | - A simple immutable dictionary. |
20 | | - |
21 | | - The API is the same as `dict`, without methods that can change the |
22 | | - immutability. In addition, it supports __hash__(). |
23 | | - """ |
24 | | - |
25 | | - __slots__ = ( |
26 | | - "_hash", |
27 | | - ) |
28 | | - |
29 | | - @classmethod |
30 | | - def fromkeys(cls, *args, **kwargs): |
31 | | - r""" |
32 | | - Identical to dict.fromkeys(). |
33 | | - """ |
34 | | - |
35 | | - return cls(dict.fromkeys(*args, **kwargs)) |
36 | | - |
37 | | - def __new__(e4b37cdf_d78a_4632_bade_6f0579d8efac, *args, **kwargs): |
38 | | - cls = e4b37cdf_d78a_4632_bade_6f0579d8efac |
39 | | - |
40 | | - has_kwargs = bool(kwargs) |
41 | | - continue_creation = True |
42 | | - |
43 | | - # check if there's only an argument and it's of the same class |
44 | | - if len(args) == 1 and not has_kwargs: |
45 | | - it = args[0] |
46 | | - |
47 | | - # no isinstance, to avoid subclassing problems |
48 | | - if it.__class__ == frozendict and cls == frozendict: |
49 | | - self = it |
50 | | - continue_creation = False |
51 | | - |
52 | | - if continue_creation: |
53 | | - self = dict.__new__(cls, *args, **kwargs) |
54 | | - |
55 | | - dict.__init__(self, *args, **kwargs) |
56 | | - |
57 | | - # empty singleton - start |
58 | | - |
59 | | - if self.__class__ == frozendict and not len(self): |
60 | | - global _empty_frozendict |
61 | | - |
62 | | - if _empty_frozendict is None: |
63 | | - _empty_frozendict = self |
64 | | - else: |
65 | | - self = _empty_frozendict |
66 | | - continue_creation = False |
67 | | - |
68 | | - # empty singleton - end |
69 | | - |
70 | | - if continue_creation: |
71 | | - object.__setattr__(self, "_hash", -1) |
72 | | - |
73 | | - return self |
74 | | - |
75 | | - def __init__(self, *args, **kwargs): |
76 | | - pass |
77 | | - |
78 | | - def __hash__(self, *args, **kwargs): |
79 | | - r""" |
80 | | - Calculates the hash if all values are hashable, otherwise |
81 | | - raises a TypeError. |
82 | | - """ |
83 | | - |
84 | | - if self._hash != -1: |
85 | | - _hash = self._hash |
86 | | - else: |
87 | | - fs = frozenset(self.items()) |
88 | | - _hash = hash(fs) |
89 | | - |
90 | | - object.__setattr__(self, "_hash", _hash) |
91 | | - |
92 | | - return _hash |
93 | | - |
94 | | - def __repr__(self, *args, **kwargs): |
95 | | - r""" |
96 | | - Identical to dict.__repr__(). |
97 | | - """ |
98 | | - |
99 | | - body = super().__repr__(*args, **kwargs) |
100 | | - klass = self.__class__ |
101 | | - |
102 | | - if klass == frozendict: |
103 | | - name = f"frozendict.{klass.__name__}" |
104 | | - else: |
105 | | - name = klass.__name__ |
106 | | - |
107 | | - return f"{name}({body})" |
108 | | - |
109 | | - def copy(self): |
110 | | - r""" |
111 | | - Return the object itself, as it's an immutable. |
112 | | - """ |
113 | | - |
114 | | - klass = self.__class__ |
115 | | - |
116 | | - if klass == frozendict: |
117 | | - return self |
118 | | - |
119 | | - return klass(self) |
120 | | - |
121 | | - def __copy__(self, *args, **kwargs): |
122 | | - r""" |
123 | | - See copy(). |
124 | | - """ |
125 | | - |
126 | | - return self.copy() |
127 | | - |
128 | | - def __deepcopy__(self, memo, *args, **kwargs): |
129 | | - r""" |
130 | | - As for tuples, if hashable, see copy(); otherwise, it returns a |
131 | | - deepcopy. |
132 | | - """ |
133 | | - |
134 | | - klass = self.__class__ |
135 | | - return_copy = klass == frozendict |
136 | | - |
137 | | - if return_copy: |
138 | | - try: |
139 | | - hash(self) |
140 | | - except TypeError: |
141 | | - return_copy = False |
142 | | - |
143 | | - if return_copy: |
144 | | - return self.copy() |
145 | | - |
146 | | - tmp = deepcopy(dict(self)) |
147 | | - |
148 | | - return klass(tmp) |
149 | | - |
150 | | - def __reduce__(self, *args, **kwargs): |
151 | | - r""" |
152 | | - Support for `pickle`. |
153 | | - """ |
154 | | - |
155 | | - return (self.__class__, (dict(self), )) |
156 | | - |
157 | | - def set(self, key, val): |
158 | | - new_self = deepcopy(dict(self)) |
159 | | - new_self[key] = val |
160 | | - |
161 | | - return self.__class__(new_self) |
162 | | - |
163 | | - def setdefault(self, key, default=None): |
164 | | - if key in self: |
165 | | - return self |
166 | | - |
167 | | - new_self = deepcopy(dict(self)) |
168 | | - |
169 | | - new_self[key] = default |
170 | | - |
171 | | - return self.__class__(new_self) |
172 | | - |
173 | | - def delete(self, key): |
174 | | - new_self = deepcopy(dict(self)) |
175 | | - del new_self[key] |
176 | | - |
177 | | - if new_self: |
178 | | - return self.__class__(new_self) |
179 | | - |
180 | | - return self.__class__() |
181 | | - |
182 | | - def _get_by_index(self, collection, index): |
183 | | - try: |
184 | | - return collection[index] |
185 | | - except IndexError: |
186 | | - maxindex = len(collection) - 1 |
187 | | - name = self.__class__.__name__ |
188 | | - raise IndexError( |
189 | | - f"{name} index {index} out of range {maxindex}" |
190 | | - ) from None |
191 | | - |
192 | | - def key(self, index=0): |
193 | | - collection = tuple(self.keys()) |
194 | | - |
195 | | - return self._get_by_index(collection, index) |
196 | | - |
197 | | - def value(self, index=0): |
198 | | - collection = tuple(self.values()) |
199 | | - |
200 | | - return self._get_by_index(collection, index) |
201 | | - |
202 | | - def item(self, index=0): |
203 | | - collection = tuple(self.items()) |
204 | | - |
205 | | - return self._get_by_index(collection, index) |
206 | | - |
207 | | - def __setitem__(self, key, val, *args, **kwargs): |
208 | | - raise TypeError( |
209 | | - f"'{self.__class__.__name__}' object doesn't support item " |
210 | | - "assignment" |
211 | | - ) |
212 | | - |
213 | | - def __delitem__(self, key, *args, **kwargs): |
214 | | - raise TypeError( |
215 | | - f"'{self.__class__.__name__}' object doesn't support item " |
216 | | - "deletion" |
217 | | - ) |
218 | | - |
219 | | - |
220 | | -def frozendict_or(self, other, *args, **kwargs): |
221 | | - res = {} |
222 | | - res.update(self) |
223 | | - res.update(other) |
224 | | - |
225 | | - return self.__class__(res) |
226 | | - |
227 | | - |
228 | | -frozendict.__or__ = frozendict_or |
229 | | -frozendict.__ior__ = frozendict_or |
230 | | - |
231 | | -try: |
232 | | - frozendict.__reversed__ |
233 | | -except AttributeError: |
234 | | - def frozendict_reversed(self, *args, **kwargs): |
235 | | - return reversed(tuple(self)) |
236 | | - |
237 | | - frozendict.__reversed__ = frozendict_reversed |
238 | | - |
239 | | - |
240 | | -frozendict.clear = immutable |
241 | | -frozendict.pop = immutable |
242 | | -frozendict.popitem = immutable |
243 | | -frozendict.update = immutable |
244 | | -frozendict.__delattr__ = immutable |
245 | | -frozendict.__setattr__ = immutable |
246 | | -frozendict.__module__ = 'frozendict' |
247 | | - |
248 | | -__all__ = (frozendict.__name__, ) |
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