Coverage for python/lsst/pex/config/dictField.py: 23%
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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 Config, Field, FieldValidationError, _autocast, _joinNamePath, _typeStr
38class Dict(collections.abc.MutableMapping):
39 """An internal mapping container.
41 This class emulates a `dict`, but adds validation and provenance.
42 """
44 def __init__(self, config, field, value, at, label, setHistory=True):
45 self._field = field
46 self._config_ = weakref.ref(config)
47 self._dict = {}
48 self._history = self._config._history.setdefault(self._field.name, [])
49 self.__doc__ = field.doc
50 if value is not None:
51 try:
52 for k in value:
53 # do not set history per-item
54 self.__setitem__(k, value[k], at=at, label=label, setHistory=False)
55 except TypeError:
56 msg = "Value %s is of incorrect type %s. Mapping type expected." % (value, _typeStr(value))
57 raise FieldValidationError(self._field, self._config, msg)
58 if setHistory:
59 self._history.append((dict(self._dict), at, label))
61 @property
62 def _config(self) -> Config:
63 # Config Fields should never outlive their config class instance
64 # assert that as such here
65 assert self._config_() is not None
66 return self._config_()
68 history = property(lambda x: x._history) 68 ↛ exitline 68 didn't run the lambda on line 68
69 """History (read-only).
70 """
72 def __getitem__(self, k):
73 return self._dict[k]
75 def __len__(self):
76 return len(self._dict)
78 def __iter__(self):
79 return iter(self._dict)
81 def __contains__(self, k):
82 return k in self._dict
84 def __setitem__(self, k, x, at=None, label="setitem", setHistory=True):
85 if self._config._frozen:
86 msg = "Cannot modify a frozen Config. Attempting to set item at key %r to value %s" % (k, x)
87 raise FieldValidationError(self._field, self._config, msg)
89 # validate keytype
90 k = _autocast(k, self._field.keytype)
91 if type(k) != self._field.keytype:
92 msg = "Key %r is of type %s, expected type %s" % (k, _typeStr(k), _typeStr(self._field.keytype))
93 raise FieldValidationError(self._field, self._config, msg)
95 # validate itemtype
96 x = _autocast(x, self._field.itemtype)
97 if self._field.itemtype is None:
98 if type(x) not in self._field.supportedTypes and x is not None:
99 msg = "Value %s at key %r is of invalid type %s" % (x, k, _typeStr(x))
100 raise FieldValidationError(self._field, self._config, msg)
101 else:
102 if type(x) != self._field.itemtype and x is not None:
103 msg = "Value %s at key %r is of incorrect type %s. Expected type %s" % (
104 x,
105 k,
106 _typeStr(x),
107 _typeStr(self._field.itemtype),
108 )
109 raise FieldValidationError(self._field, self._config, msg)
111 # validate item using itemcheck
112 if self._field.itemCheck is not None and not self._field.itemCheck(x):
113 msg = "Item at key %r is not a valid value: %s" % (k, x)
114 raise FieldValidationError(self._field, self._config, msg)
116 if at is None:
117 at = getCallStack()
119 self._dict[k] = x
120 if setHistory:
121 self._history.append((dict(self._dict), at, label))
123 def __delitem__(self, k, at=None, label="delitem", setHistory=True):
124 if self._config._frozen:
125 raise FieldValidationError(self._field, self._config, "Cannot modify a frozen Config")
127 del self._dict[k]
128 if setHistory:
129 if at is None:
130 at = getCallStack()
131 self._history.append((dict(self._dict), at, label))
133 def __repr__(self):
134 return repr(self._dict)
136 def __str__(self):
137 return str(self._dict)
139 def __setattr__(self, attr, value, at=None, label="assignment"):
140 if hasattr(getattr(self.__class__, attr, None), "__set__"):
141 # This allows properties to work.
142 object.__setattr__(self, attr, value)
143 elif attr in self.__dict__ or attr in ["_field", "_config_", "_history", "_dict", "__doc__"]:
144 # This allows specific private attributes to work.
145 object.__setattr__(self, attr, value)
146 else:
147 # We throw everything else.
148 msg = "%s has no attribute %s" % (_typeStr(self._field), attr)
149 raise FieldValidationError(self._field, self._config, msg)
152class DictField(Field):
153 """A configuration field (`~lsst.pex.config.Field` subclass) that maps keys
154 and values.
156 The types of both items and keys are restricted to these builtin types:
157 `int`, `float`, `complex`, `bool`, and `str`). All keys share the same type
158 and all values share the same type. Keys can have a different type from
159 values.
161 Parameters
162 ----------
163 doc : `str`
164 A documentation string that describes the configuration field.
165 keytype : {`int`, `float`, `complex`, `bool`, `str`}
166 The type of the mapping keys. All keys must have this type.
167 itemtype : {`int`, `float`, `complex`, `bool`, `str`}
168 Type of the mapping values.
169 default : `dict`, optional
170 The default mapping.
171 optional : `bool`, optional
172 If `True`, the field doesn't need to have a set value.
173 dictCheck : callable
174 A function that validates the dictionary as a whole.
175 itemCheck : callable
176 A function that validates individual mapping values.
177 deprecated : None or `str`, optional
178 A description of why this Field is deprecated, including removal date.
179 If not None, the string is appended to the docstring for this Field.
181 See also
182 --------
183 ChoiceField
184 ConfigChoiceField
185 ConfigDictField
186 ConfigField
187 ConfigurableField
188 Field
189 ListField
190 RangeField
191 RegistryField
193 Examples
194 --------
195 This field maps has `str` keys and `int` values:
197 >>> from lsst.pex.config import Config, DictField
198 >>> class MyConfig(Config):
199 ... field = DictField(
200 ... doc="Example string-to-int mapping field.",
201 ... keytype=str, itemtype=int,
202 ... default={})
203 ...
204 >>> config = MyConfig()
205 >>> config.field['myKey'] = 42
206 >>> print(config.field)
207 {'myKey': 42}
208 """
210 DictClass = Dict
212 def __init__(
213 self,
214 doc,
215 keytype,
216 itemtype,
217 default=None,
218 optional=False,
219 dictCheck=None,
220 itemCheck=None,
221 deprecated=None,
222 ):
223 source = getStackFrame()
224 self._setup(
225 doc=doc,
226 dtype=Dict,
227 default=default,
228 check=None,
229 optional=optional,
230 source=source,
231 deprecated=deprecated,
232 )
233 if keytype not in self.supportedTypes: 233 ↛ 234line 233 didn't jump to line 234, because the condition on line 233 was never true
234 raise ValueError("'keytype' %s is not a supported type" % _typeStr(keytype))
235 elif itemtype is not None and itemtype not in self.supportedTypes: 235 ↛ 236line 235 didn't jump to line 236, because the condition on line 235 was never true
236 raise ValueError("'itemtype' %s is not a supported type" % _typeStr(itemtype))
237 if dictCheck is not None and not hasattr(dictCheck, "__call__"): 237 ↛ 238line 237 didn't jump to line 238, because the condition on line 237 was never true
238 raise ValueError("'dictCheck' must be callable")
239 if itemCheck is not None and not hasattr(itemCheck, "__call__"): 239 ↛ 240line 239 didn't jump to line 240, because the condition on line 239 was never true
240 raise ValueError("'itemCheck' must be callable")
242 self.keytype = keytype
243 self.itemtype = itemtype
244 self.dictCheck = dictCheck
245 self.itemCheck = itemCheck
247 def validate(self, instance):
248 """Validate the field's value (for internal use only).
250 Parameters
251 ----------
252 instance : `lsst.pex.config.Config`
253 The configuration that contains this field.
255 Returns
256 -------
257 isValid : `bool`
258 `True` is returned if the field passes validation criteria (see
259 *Notes*). Otherwise `False`.
261 Notes
262 -----
263 This method validates values according to the following criteria:
265 - A non-optional field is not `None`.
266 - If a value is not `None`, is must pass the `ConfigField.dictCheck`
267 user callback functon.
269 Individual item checks by the `ConfigField.itemCheck` user callback
270 function are done immediately when the value is set on a key. Those
271 checks are not repeated by this method.
272 """
273 Field.validate(self, instance)
274 value = self.__get__(instance)
275 if value is not None and self.dictCheck is not None and not self.dictCheck(value):
276 msg = "%s is not a valid value" % str(value)
277 raise FieldValidationError(self, instance, msg)
279 def __set__(self, instance, value, at=None, label="assignment"):
280 if instance._frozen:
281 msg = "Cannot modify a frozen Config. Attempting to set field to value %s" % value
282 raise FieldValidationError(self, instance, msg)
284 if at is None:
285 at = getCallStack()
286 if value is not None:
287 value = self.DictClass(instance, self, value, at=at, label=label)
288 else:
289 history = instance._history.setdefault(self.name, [])
290 history.append((value, at, label))
292 instance._storage[self.name] = value
294 def toDict(self, instance):
295 """Convert this field's key-value pairs into a regular `dict`.
297 Parameters
298 ----------
299 instance : `lsst.pex.config.Config`
300 The configuration that contains this field.
302 Returns
303 -------
304 result : `dict` or `None`
305 If this field has a value of `None`, then this method returns
306 `None`. Otherwise, this method returns the field's value as a
307 regular Python `dict`.
308 """
309 value = self.__get__(instance)
310 return dict(value) if value is not None else None
312 def _compare(self, instance1, instance2, shortcut, rtol, atol, output):
313 """Compare two fields for equality.
315 Used by `lsst.pex.ConfigDictField.compare`.
317 Parameters
318 ----------
319 instance1 : `lsst.pex.config.Config`
320 Left-hand side config instance to compare.
321 instance2 : `lsst.pex.config.Config`
322 Right-hand side config instance to compare.
323 shortcut : `bool`
324 If `True`, this function returns as soon as an inequality if found.
325 rtol : `float`
326 Relative tolerance for floating point comparisons.
327 atol : `float`
328 Absolute tolerance for floating point comparisons.
329 output : callable
330 A callable that takes a string, used (possibly repeatedly) to
331 report inequalities.
333 Returns
334 -------
335 isEqual : bool
336 `True` if the fields are equal, `False` otherwise.
338 Notes
339 -----
340 Floating point comparisons are performed by `numpy.allclose`.
341 """
342 d1 = getattr(instance1, self.name)
343 d2 = getattr(instance2, self.name)
344 name = getComparisonName(
345 _joinNamePath(instance1._name, self.name), _joinNamePath(instance2._name, self.name)
346 )
347 if not compareScalars("isnone for %s" % name, d1 is None, d2 is None, output=output):
348 return False
349 if d1 is None and d2 is None:
350 return True
351 if not compareScalars("keys for %s" % name, set(d1.keys()), set(d2.keys()), output=output):
352 return False
353 equal = True
354 for k, v1 in d1.items():
355 v2 = d2[k]
356 result = compareScalars(
357 "%s[%r]" % (name, k), v1, v2, dtype=self.itemtype, rtol=rtol, atol=atol, output=output
358 )
359 if not result and shortcut:
360 return False
361 equal = equal and result
362 return equal