Coverage for python/lsst/pex/config/dictField.py: 24%
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1# This file is part of pex_config.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This software is dual licensed under the GNU General Public License and also
10# under a 3-clause BSD license. Recipients may choose which of these licenses
11# to use; please see the files gpl-3.0.txt and/or bsd_license.txt,
12# respectively. If you choose the GPL option then the following text applies
13# (but note that there is still no warranty even if you opt for BSD instead):
14#
15# This program is free software: you can redistribute it and/or modify
16# it under the terms of the GNU General Public License as published by
17# the Free Software Foundation, either version 3 of the License, or
18# (at your option) any later version.
19#
20# This program is distributed in the hope that it will be useful,
21# but WITHOUT ANY WARRANTY; without even the implied warranty of
22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23# GNU General Public License for more details.
24#
25# You should have received a copy of the GNU General Public License
26# along with this program. If not, see <http://www.gnu.org/licenses/>.
28__all__ = ["DictField"]
30import collections.abc
31import weakref
33from .callStack import getCallStack, getStackFrame
34from .comparison import compareScalars, getComparisonName
35from .config import (
36 Config,
37 Field,
38 FieldValidationError,
39 UnexpectedProxyUsageError,
40 _autocast,
41 _joinNamePath,
42 _typeStr,
43)
46class Dict(collections.abc.MutableMapping):
47 """An internal mapping container.
49 This class emulates a `dict`, but adds validation and provenance.
50 """
52 def __init__(self, config, field, value, at, label, setHistory=True):
53 self._field = field
54 self._config_ = weakref.ref(config)
55 self._dict = {}
56 self._history = self._config._history.setdefault(self._field.name, [])
57 self.__doc__ = field.doc
58 if value is not None:
59 try:
60 for k in value:
61 # do not set history per-item
62 self.__setitem__(k, value[k], at=at, label=label, setHistory=False)
63 except TypeError:
64 msg = "Value %s is of incorrect type %s. Mapping type expected." % (value, _typeStr(value))
65 raise FieldValidationError(self._field, self._config, msg)
66 if setHistory:
67 self._history.append((dict(self._dict), at, label))
69 @property
70 def _config(self) -> Config:
71 # Config Fields should never outlive their config class instance
72 # assert that as such here
73 assert self._config_() is not None
74 return self._config_()
76 history = property(lambda x: x._history) 76 ↛ exitline 76 didn't run the lambda on line 76
77 """History (read-only).
78 """
80 def __getitem__(self, k):
81 return self._dict[k]
83 def __len__(self):
84 return len(self._dict)
86 def __iter__(self):
87 return iter(self._dict)
89 def __contains__(self, k):
90 return k in self._dict
92 def __setitem__(self, k, x, at=None, label="setitem", setHistory=True):
93 if self._config._frozen:
94 msg = "Cannot modify a frozen Config. Attempting to set item at key %r to value %s" % (k, x)
95 raise FieldValidationError(self._field, self._config, msg)
97 # validate keytype
98 k = _autocast(k, self._field.keytype)
99 if type(k) != self._field.keytype:
100 msg = "Key %r is of type %s, expected type %s" % (k, _typeStr(k), _typeStr(self._field.keytype))
101 raise FieldValidationError(self._field, self._config, msg)
103 # validate itemtype
104 x = _autocast(x, self._field.itemtype)
105 if self._field.itemtype is None:
106 if type(x) not in self._field.supportedTypes and x is not None:
107 msg = "Value %s at key %r is of invalid type %s" % (x, k, _typeStr(x))
108 raise FieldValidationError(self._field, self._config, msg)
109 else:
110 if type(x) != self._field.itemtype and x is not None:
111 msg = "Value %s at key %r is of incorrect type %s. Expected type %s" % (
112 x,
113 k,
114 _typeStr(x),
115 _typeStr(self._field.itemtype),
116 )
117 raise FieldValidationError(self._field, self._config, msg)
119 # validate item using itemcheck
120 if self._field.itemCheck is not None and not self._field.itemCheck(x):
121 msg = "Item at key %r is not a valid value: %s" % (k, x)
122 raise FieldValidationError(self._field, self._config, msg)
124 if at is None:
125 at = getCallStack()
127 self._dict[k] = x
128 if setHistory:
129 self._history.append((dict(self._dict), at, label))
131 def __delitem__(self, k, at=None, label="delitem", setHistory=True):
132 if self._config._frozen:
133 raise FieldValidationError(self._field, self._config, "Cannot modify a frozen Config")
135 del self._dict[k]
136 if setHistory:
137 if at is None:
138 at = getCallStack()
139 self._history.append((dict(self._dict), at, label))
141 def __repr__(self):
142 return repr(self._dict)
144 def __str__(self):
145 return str(self._dict)
147 def __setattr__(self, attr, value, at=None, label="assignment"):
148 if hasattr(getattr(self.__class__, attr, None), "__set__"):
149 # This allows properties to work.
150 object.__setattr__(self, attr, value)
151 elif attr in self.__dict__ or attr in ["_field", "_config_", "_history", "_dict", "__doc__"]:
152 # This allows specific private attributes to work.
153 object.__setattr__(self, attr, value)
154 else:
155 # We throw everything else.
156 msg = "%s has no attribute %s" % (_typeStr(self._field), attr)
157 raise FieldValidationError(self._field, self._config, msg)
159 def __reduce__(self):
160 raise UnexpectedProxyUsageError(
161 f"Proxy container for config field {self._field.name} cannot "
162 "be pickled; it should be converted to a built-in container before "
163 "being assigned to other objects or variables."
164 )
167class DictField(Field):
168 """A configuration field (`~lsst.pex.config.Field` subclass) that maps keys
169 and values.
171 The types of both items and keys are restricted to these builtin types:
172 `int`, `float`, `complex`, `bool`, and `str`). All keys share the same type
173 and all values share the same type. Keys can have a different type from
174 values.
176 Parameters
177 ----------
178 doc : `str`
179 A documentation string that describes the configuration field.
180 keytype : {`int`, `float`, `complex`, `bool`, `str`}
181 The type of the mapping keys. All keys must have this type.
182 itemtype : {`int`, `float`, `complex`, `bool`, `str`}
183 Type of the mapping values.
184 default : `dict`, optional
185 The default mapping.
186 optional : `bool`, optional
187 If `True`, the field doesn't need to have a set value.
188 dictCheck : callable
189 A function that validates the dictionary as a whole.
190 itemCheck : callable
191 A function that validates individual mapping values.
192 deprecated : None or `str`, optional
193 A description of why this Field is deprecated, including removal date.
194 If not None, the string is appended to the docstring for this Field.
196 See also
197 --------
198 ChoiceField
199 ConfigChoiceField
200 ConfigDictField
201 ConfigField
202 ConfigurableField
203 Field
204 ListField
205 RangeField
206 RegistryField
208 Examples
209 --------
210 This field maps has `str` keys and `int` values:
212 >>> from lsst.pex.config import Config, DictField
213 >>> class MyConfig(Config):
214 ... field = DictField(
215 ... doc="Example string-to-int mapping field.",
216 ... keytype=str, itemtype=int,
217 ... default={})
218 ...
219 >>> config = MyConfig()
220 >>> config.field['myKey'] = 42
221 >>> print(config.field)
222 {'myKey': 42}
223 """
225 DictClass = Dict
227 def __init__(
228 self,
229 doc,
230 keytype,
231 itemtype,
232 default=None,
233 optional=False,
234 dictCheck=None,
235 itemCheck=None,
236 deprecated=None,
237 ):
238 source = getStackFrame()
239 self._setup(
240 doc=doc,
241 dtype=Dict,
242 default=default,
243 check=None,
244 optional=optional,
245 source=source,
246 deprecated=deprecated,
247 )
248 if keytype not in self.supportedTypes: 248 ↛ 249line 248 didn't jump to line 249, because the condition on line 248 was never true
249 raise ValueError("'keytype' %s is not a supported type" % _typeStr(keytype))
250 elif itemtype is not None and itemtype not in self.supportedTypes: 250 ↛ 251line 250 didn't jump to line 251, because the condition on line 250 was never true
251 raise ValueError("'itemtype' %s is not a supported type" % _typeStr(itemtype))
252 if dictCheck is not None and not hasattr(dictCheck, "__call__"): 252 ↛ 253line 252 didn't jump to line 253, because the condition on line 252 was never true
253 raise ValueError("'dictCheck' must be callable")
254 if itemCheck is not None and not hasattr(itemCheck, "__call__"): 254 ↛ 255line 254 didn't jump to line 255, because the condition on line 254 was never true
255 raise ValueError("'itemCheck' must be callable")
257 self.keytype = keytype
258 self.itemtype = itemtype
259 self.dictCheck = dictCheck
260 self.itemCheck = itemCheck
262 def validate(self, instance):
263 """Validate the field's value (for internal use only).
265 Parameters
266 ----------
267 instance : `lsst.pex.config.Config`
268 The configuration that contains this field.
270 Returns
271 -------
272 isValid : `bool`
273 `True` is returned if the field passes validation criteria (see
274 *Notes*). Otherwise `False`.
276 Notes
277 -----
278 This method validates values according to the following criteria:
280 - A non-optional field is not `None`.
281 - If a value is not `None`, is must pass the `ConfigField.dictCheck`
282 user callback functon.
284 Individual item checks by the `ConfigField.itemCheck` user callback
285 function are done immediately when the value is set on a key. Those
286 checks are not repeated by this method.
287 """
288 Field.validate(self, instance)
289 value = self.__get__(instance)
290 if value is not None and self.dictCheck is not None and not self.dictCheck(value):
291 msg = "%s is not a valid value" % str(value)
292 raise FieldValidationError(self, instance, msg)
294 def __set__(self, instance, value, at=None, label="assignment"):
295 if instance._frozen:
296 msg = "Cannot modify a frozen Config. Attempting to set field to value %s" % value
297 raise FieldValidationError(self, instance, msg)
299 if at is None:
300 at = getCallStack()
301 if value is not None:
302 value = self.DictClass(instance, self, value, at=at, label=label)
303 else:
304 history = instance._history.setdefault(self.name, [])
305 history.append((value, at, label))
307 instance._storage[self.name] = value
309 def toDict(self, instance):
310 """Convert this field's key-value pairs into a regular `dict`.
312 Parameters
313 ----------
314 instance : `lsst.pex.config.Config`
315 The configuration that contains this field.
317 Returns
318 -------
319 result : `dict` or `None`
320 If this field has a value of `None`, then this method returns
321 `None`. Otherwise, this method returns the field's value as a
322 regular Python `dict`.
323 """
324 value = self.__get__(instance)
325 return dict(value) if value is not None else None
327 def _compare(self, instance1, instance2, shortcut, rtol, atol, output):
328 """Compare two fields for equality.
330 Used by `lsst.pex.ConfigDictField.compare`.
332 Parameters
333 ----------
334 instance1 : `lsst.pex.config.Config`
335 Left-hand side config instance to compare.
336 instance2 : `lsst.pex.config.Config`
337 Right-hand side config instance to compare.
338 shortcut : `bool`
339 If `True`, this function returns as soon as an inequality if found.
340 rtol : `float`
341 Relative tolerance for floating point comparisons.
342 atol : `float`
343 Absolute tolerance for floating point comparisons.
344 output : callable
345 A callable that takes a string, used (possibly repeatedly) to
346 report inequalities.
348 Returns
349 -------
350 isEqual : bool
351 `True` if the fields are equal, `False` otherwise.
353 Notes
354 -----
355 Floating point comparisons are performed by `numpy.allclose`.
356 """
357 d1 = getattr(instance1, self.name)
358 d2 = getattr(instance2, self.name)
359 name = getComparisonName(
360 _joinNamePath(instance1._name, self.name), _joinNamePath(instance2._name, self.name)
361 )
362 if not compareScalars("isnone for %s" % name, d1 is None, d2 is None, output=output):
363 return False
364 if d1 is None and d2 is None:
365 return True
366 if not compareScalars("keys for %s" % name, set(d1.keys()), set(d2.keys()), output=output):
367 return False
368 equal = True
369 for k, v1 in d1.items():
370 v2 = d2[k]
371 result = compareScalars(
372 "%s[%r]" % (name, k), v1, v2, dtype=self.itemtype, rtol=rtol, atol=atol, output=output
373 )
374 if not result and shortcut:
375 return False
376 equal = equal and result
377 return equal