Repository navigation
Expand file tree
/
Copy path_funcs.py
More file actions
495 lines (426 loc) · 16 KB
/
Copy path_funcs.py
File metadata and controls
495 lines (426 loc) · 16 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
# SPDX-License-Identifier: MIT
from ._compat import get_generic_base
from ._make import _OBJ_SETATTR, NOTHING, fields
from .exceptions import AttrsAttributeNotFoundError
_ATOMIC_TYPES = frozenset(
{
type(None),
bool,
int,
float,
str,
complex,
bytes,
type(...),
type,
range,
property,
}
)
def asdict(
inst,
recurse=True,
filter=None,
dict_factory=dict,
retain_collection_types=False,
value_serializer=None,
):
"""
Return the *attrs* attribute values of *inst* as a dict.
Optionally recurse into other *attrs*-decorated classes.
Args:
inst: Instance of an *attrs*-decorated class.
recurse (bool): Recurse into classes that are also *attrs*-decorated.
filter (~typing.Callable):
A callable whose return code determines whether an attribute or
element is included (`True`) or dropped (`False`). Is called with
the `attrs.Attribute` as the first argument and the value as the
second argument.
dict_factory (~typing.Callable):
A callable to produce dictionaries from. For example, to produce
ordered dictionaries instead of normal Python dictionaries, pass in
``collections.OrderedDict``.
retain_collection_types (bool):
Do not convert to `list` when encountering an attribute whose type
is `tuple` or `set`. Only meaningful if *recurse* is `True`.
value_serializer (typing.Callable | None):
A hook that is called for every attribute or dict key/value. It
receives the current instance, field and value and must return the
(updated) value. The hook is run *after* the optional *filter* has
been applied.
Returns:
Return type of *dict_factory*.
Raises:
attrs.exceptions.NotAnAttrsClassError:
If *cls* is not an *attrs* class.
.. versionadded:: 16.0.0 *dict_factory*
.. versionadded:: 16.1.0 *retain_collection_types*
.. versionadded:: 20.3.0 *value_serializer*
.. versionadded:: 21.3.0
If a dict has a collection for a key, it is serialized as a tuple.
"""
attrs = fields(inst.__class__)
rv = dict_factory()
for a in attrs:
v = getattr(inst, a.name)
if filter is not None and not filter(a, v):
continue
if value_serializer is not None:
v = value_serializer(inst, a, v)
if recurse is True:
value_type = type(v)
if value_type in _ATOMIC_TYPES:
rv[a.name] = v
elif has(value_type):
rv[a.name] = asdict(
v,
recurse=True,
filter=filter,
dict_factory=dict_factory,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
)
elif issubclass(value_type, (tuple, list, set, frozenset)):
cf = value_type if retain_collection_types is True else list
items = [
_asdict_anything(
i,
is_key=False,
filter=filter,
dict_factory=dict_factory,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
)
for i in v
]
try:
rv[a.name] = cf(items)
except TypeError:
if not issubclass(cf, tuple):
raise
# Workaround for TypeError: cf.__new__() missing 1 required
# positional argument (which appears, for a namedturle)
rv[a.name] = cf(*items)
elif issubclass(value_type, dict):
df = dict_factory
rv[a.name] = df(
(
_asdict_anything(
kk,
is_key=True,
filter=filter,
dict_factory=df,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
),
_asdict_anything(
vv,
is_key=False,
filter=filter,
dict_factory=df,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
),
)
for kk, vv in v.items()
)
else:
rv[a.name] = v
else:
rv[a.name] = v
return rv
def _asdict_anything(
val,
is_key,
filter,
dict_factory,
retain_collection_types,
value_serializer,
):
"""
``asdict`` only works on attrs instances, this works on anything.
"""
val_type = type(val)
if val_type in _ATOMIC_TYPES:
rv = val
if value_serializer is not None:
rv = value_serializer(None, None, rv)
elif getattr(val_type, "__attrs_attrs__", None) is not None:
# Attrs class.
rv = asdict(
val,
recurse=True,
filter=filter,
dict_factory=dict_factory,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
)
elif issubclass(val_type, (tuple, list, set, frozenset)):
if retain_collection_types is True:
cf = val.__class__
elif is_key:
cf = tuple
else:
cf = list
rv = cf(
[
_asdict_anything(
i,
is_key=False,
filter=filter,
dict_factory=dict_factory,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
)
for i in val
]
)
elif issubclass(val_type, dict):
df = dict_factory
rv = df(
(
_asdict_anything(
kk,
is_key=True,
filter=filter,
dict_factory=df,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
),
_asdict_anything(
vv,
is_key=False,
filter=filter,
dict_factory=df,
retain_collection_types=retain_collection_types,
value_serializer=value_serializer,
),
)
for kk, vv in val.items()
)
else:
rv = val
if value_serializer is not None:
rv = value_serializer(None, None, rv)
return rv
def astuple(
inst,
recurse=True,
filter=None,
tuple_factory=tuple,
retain_collection_types=False,
):
"""
Return the *attrs* attribute values of *inst* as a tuple.
Optionally recurse into other *attrs*-decorated classes.
Args:
inst: Instance of an *attrs*-decorated class.
recurse (bool):
Recurse into classes that are also *attrs*-decorated.
filter (~typing.Callable):
A callable whose return code determines whether an attribute or
element is included (`True`) or dropped (`False`). Is called with
the `attrs.Attribute` as the first argument and the value as the
second argument.
tuple_factory (~typing.Callable):
A callable to produce tuples from. For example, to produce lists
instead of tuples.
retain_collection_types (bool):
Do not convert to `list` or `dict` when encountering an attribute
which type is `tuple`, `dict` or `set`. Only meaningful if
*recurse* is `True`.
Returns:
Return type of *tuple_factory*
Raises:
attrs.exceptions.NotAnAttrsClassError:
If *cls* is not an *attrs* class.
.. versionadded:: 16.2.0
"""
attrs = fields(inst.__class__)
rv = []
retain = retain_collection_types # Very long. :/
for a in attrs:
v = getattr(inst, a.name)
if filter is not None and not filter(a, v):
continue
value_type = type(v)
if recurse is True:
if value_type in _ATOMIC_TYPES:
rv.append(v)
elif has(value_type):
rv.append(
astuple(
v,
recurse=True,
filter=filter,
tuple_factory=tuple_factory,
retain_collection_types=retain,
)
)
elif issubclass(value_type, (tuple, list, set, frozenset)):
cf = v.__class__ if retain is True else list
items = [
(
astuple(
j,
recurse=True,
filter=filter,
tuple_factory=tuple_factory,
retain_collection_types=retain,
)
if type(j) not in _ATOMIC_TYPES and has(j.__class__)
else j
)
for j in v
]
try:
rv.append(cf(items))
except TypeError:
if not issubclass(cf, tuple):
raise
# Workaround for TypeError: cf.__new__() missing 1 required
# positional argument (which appears, for a namedturle)
rv.append(cf(*items))
elif issubclass(value_type, dict):
df = value_type if retain is True else dict
rv.append(
df(
(
(
astuple(
kk,
tuple_factory=tuple_factory,
retain_collection_types=retain,
)
if has(kk.__class__)
else kk
),
(
astuple(
vv,
tuple_factory=tuple_factory,
retain_collection_types=retain,
)
if has(vv.__class__)
else vv
),
)
for kk, vv in v.items()
)
)
else:
rv.append(v)
else:
rv.append(v)
return rv if tuple_factory is list else tuple_factory(rv)
def has(cls):
"""
Check whether *cls* is a class with *attrs* attributes.
Args:
cls (type): Class to introspect.
Raises:
TypeError: If *cls* is not a class.
Returns:
bool:
"""
attrs = getattr(cls, "__attrs_attrs__", None)
if attrs is not None:
return True
# No attrs, maybe it's a specialized generic (A[str])?
generic_base = get_generic_base(cls)
if generic_base is not None:
generic_attrs = getattr(generic_base, "__attrs_attrs__", None)
if generic_attrs is not None:
# Stick it on here for speed next time.
cls.__attrs_attrs__ = generic_attrs
return generic_attrs is not None
return False
def assoc(inst, **changes):
"""
Copy *inst* and apply *changes*.
This is different from `evolve` that applies the changes to the arguments
that create the new instance.
`evolve`'s behavior is preferable, but there are `edge cases`_ where it
doesn't work. Therefore `assoc` is deprecated, but will not be removed.
.. _`edge cases`: https://github.com/python-attrs/attrs/issues/251
Args:
inst: Instance of a class with *attrs* attributes.
changes: Keyword changes in the new copy.
Returns:
A copy of inst with *changes* incorporated.
Raises:
attrs.exceptions.AttrsAttributeNotFoundError:
If *attr_name* couldn't be found on *cls*.
attrs.exceptions.NotAnAttrsClassError:
If *cls* is not an *attrs* class.
.. deprecated:: 17.1.0
Use `attrs.evolve` instead if you can. This function will not be
removed du to the slightly different approach compared to
`attrs.evolve`, though.
"""
import copy
new = copy.copy(inst)
attrs = fields(inst.__class__)
for k, v in changes.items():
a = getattr(attrs, k, NOTHING)
if a is NOTHING:
msg = f"{k} is not an attrs attribute on {new.__class__}."
raise AttrsAttributeNotFoundError(msg)
_OBJ_SETATTR(new, k, v)
return new
def resolve_types(
cls, globalns=None, localns=None, attribs=None, include_extras=True
):
"""
Resolve any strings and forward annotations in type annotations.
This is only required if you need concrete types in :class:`Attribute`'s
*type* field. In other words, you don't need to resolve your types if you
only use them for static type checking.
With no arguments, names will be looked up in the module in which the class
was created. If this is not what you want, for example, if the name only
exists inside a method, you may pass *globalns* or *localns* to specify
other dictionaries in which to look up these names. See the docs of
`typing.get_type_hints` for more details.
Args:
cls (type): Class to resolve.
globalns (dict | None): Dictionary containing global variables.
localns (dict | None): Dictionary containing local variables.
attribs (list | None):
List of attribs for the given class. This is necessary when calling
from inside a ``field_transformer`` since *cls* is not an *attrs*
class yet.
include_extras (bool):
Resolve more accurately by passing ``include_extras=True`` to
`typing.get_type_hints`.
Raises:
TypeError: If *cls* is not a class.
attrs.exceptions.NotAnAttrsClassError:
If *cls* is not an *attrs* class and you didn't pass any attribs.
NameError: If types cannot be resolved because of missing variables.
Returns:
*cls* so you can use this function also as a class decorator. Please
note that you have to apply it **after** `attrs.define`. That means the
decorator has to come in the line **before** `attrs.define`.
.. versionadded:: 20.1.0
.. versionadded:: 21.1.0 *attribs*
.. versionadded:: 23.1.0 *include_extras*
"""
# Since calling get_type_hints is expensive we cache whether we've
# done it already.
if getattr(cls, "__attrs_types_resolved__", None) != cls:
import typing
kwargs = {
"globalns": globalns,
"localns": localns,
"include_extras": include_extras,
}
hints = typing.get_type_hints(cls, **kwargs)
for field in fields(cls) if attribs is None else attribs:
if field.name in hints:
# Since fields have been frozen we must work around it.
_OBJ_SETATTR(field, "type", hints[field.name])
# We store the class we resolved so that subclasses know they haven't
# been resolved.
cls.__attrs_types_resolved__ = cls
# Return the class so you can use it as a decorator too.
return cls