Coverage for python/lsst/pex/config/dictField.py: 22%
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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
32from .config import Field, FieldValidationError, _typeStr, _autocast, _joinNamePath, Config
33from .comparison import getComparisonName, compareScalars
34from .callStack import getCallStack, getStackFrame
36import weakref
39class Dict(collections.abc.MutableMapping):
40 """An internal mapping container.
42 This class emulates a `dict`, but adds validation and provenance.
43 """
45 def __init__(self, config, field, value, at, label, setHistory=True):
46 self._field = field
47 self._config_ = weakref.ref(config)
48 self._dict = {}
49 self._history = self._config._history.setdefault(self._field.name, [])
50 self.__doc__ = field.doc
51 if value is not None:
52 try:
53 for k in value:
54 # do not set history per-item
55 self.__setitem__(k, value[k], at=at, label=label, setHistory=False)
56 except TypeError:
57 msg = "Value %s is of incorrect type %s. Mapping type expected." % \
58 (value, _typeStr(value))
59 raise FieldValidationError(self._field, self._config, msg)
60 if setHistory:
61 self._history.append((dict(self._dict), at, label))
63 @property
64 def _config(self) -> Config:
65 # Config Fields should never outlive their config class instance
66 # assert that as such here
67 assert(self._config_() is not None)
68 return self._config_()
70 history = property(lambda x: x._history) 70 ↛ exitline 70 didn't run the lambda on line 70
71 """History (read-only).
72 """
74 def __getitem__(self, k):
75 return self._dict[k]
77 def __len__(self):
78 return len(self._dict)
80 def __iter__(self):
81 return iter(self._dict)
83 def __contains__(self, k):
84 return k in self._dict
86 def __setitem__(self, k, x, at=None, label="setitem", setHistory=True):
87 if self._config._frozen:
88 msg = "Cannot modify a frozen Config. "\
89 "Attempting to set item at key %r to value %s" % (k, x)
90 raise FieldValidationError(self._field, self._config, msg)
92 # validate keytype
93 k = _autocast(k, self._field.keytype)
94 if type(k) != self._field.keytype:
95 msg = "Key %r is of type %s, expected type %s" % \
96 (k, _typeStr(k), _typeStr(self._field.keytype))
97 raise FieldValidationError(self._field, self._config, msg)
99 # validate itemtype
100 x = _autocast(x, self._field.itemtype)
101 if self._field.itemtype is None:
102 if type(x) not in self._field.supportedTypes and x is not None:
103 msg = "Value %s at key %r is of invalid type %s" % (x, k, _typeStr(x))
104 raise FieldValidationError(self._field, self._config, msg)
105 else:
106 if type(x) != self._field.itemtype and x is not None:
107 msg = "Value %s at key %r is of incorrect type %s. Expected type %s" % \
108 (x, k, _typeStr(x), _typeStr(self._field.itemtype))
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,
126 "Cannot modify a frozen Config")
128 del self._dict[k]
129 if setHistory:
130 if at is None:
131 at = getCallStack()
132 self._history.append((dict(self._dict), at, label))
134 def __repr__(self):
135 return repr(self._dict)
137 def __str__(self):
138 return str(self._dict)
140 def __setattr__(self, attr, value, at=None, label="assignment"):
141 if hasattr(getattr(self.__class__, attr, None), '__set__'):
142 # This allows properties to work.
143 object.__setattr__(self, attr, value)
144 elif attr in self.__dict__ or attr in ["_field", "_config_", "_history", "_dict", "__doc__"]:
145 # This allows specific private attributes to work.
146 object.__setattr__(self, attr, value)
147 else:
148 # We throw everything else.
149 msg = "%s has no attribute %s" % (_typeStr(self._field), attr)
150 raise FieldValidationError(self._field, self._config, msg)
153class DictField(Field):
154 """A configuration field (`~lsst.pex.config.Field` subclass) that maps keys
155 and values.
157 The types of both items and keys are restricted to these builtin types:
158 `int`, `float`, `complex`, `bool`, and `str`). All keys share the same type
159 and all values share the same type. Keys can have a different type from
160 values.
162 Parameters
163 ----------
164 doc : `str`
165 A documentation string that describes the configuration field.
166 keytype : {`int`, `float`, `complex`, `bool`, `str`}
167 The type of the mapping keys. All keys must have this type.
168 itemtype : {`int`, `float`, `complex`, `bool`, `str`}
169 Type of the mapping values.
170 default : `dict`, optional
171 The default mapping.
172 optional : `bool`, optional
173 If `True`, the field doesn't need to have a set value.
174 dictCheck : callable
175 A function that validates the dictionary as a whole.
176 itemCheck : callable
177 A function that validates individual mapping values.
178 deprecated : None or `str`, optional
179 A description of why this Field is deprecated, including removal date.
180 If not None, the string is appended to the docstring for this Field.
182 See also
183 --------
184 ChoiceField
185 ConfigChoiceField
186 ConfigDictField
187 ConfigField
188 ConfigurableField
189 Field
190 ListField
191 RangeField
192 RegistryField
194 Examples
195 --------
196 This field maps has `str` keys and `int` values:
198 >>> from lsst.pex.config import Config, DictField
199 >>> class MyConfig(Config):
200 ... field = DictField(
201 ... doc="Example string-to-int mapping field.",
202 ... keytype=str, itemtype=int,
203 ... default={})
204 ...
205 >>> config = MyConfig()
206 >>> config.field['myKey'] = 42
207 >>> print(config.field)
208 {'myKey': 42}
209 """
211 DictClass = Dict
213 def __init__(self, doc, keytype, itemtype, default=None, optional=False, dictCheck=None, itemCheck=None,
214 deprecated=None):
215 source = getStackFrame()
216 self._setup(doc=doc, dtype=Dict, default=default, check=None,
217 optional=optional, source=source, deprecated=deprecated)
218 if keytype not in self.supportedTypes: 218 ↛ 219line 218 didn't jump to line 219, because the condition on line 218 was never true
219 raise ValueError("'keytype' %s is not a supported type" %
220 _typeStr(keytype))
221 elif itemtype is not None and itemtype not in self.supportedTypes: 221 ↛ 222line 221 didn't jump to line 222, because the condition on line 221 was never true
222 raise ValueError("'itemtype' %s is not a supported type" %
223 _typeStr(itemtype))
224 if dictCheck is not None and not hasattr(dictCheck, "__call__"): 224 ↛ 225line 224 didn't jump to line 225, because the condition on line 224 was never true
225 raise ValueError("'dictCheck' must be callable")
226 if itemCheck is not None and not hasattr(itemCheck, "__call__"): 226 ↛ 227line 226 didn't jump to line 227, because the condition on line 226 was never true
227 raise ValueError("'itemCheck' must be callable")
229 self.keytype = keytype
230 self.itemtype = itemtype
231 self.dictCheck = dictCheck
232 self.itemCheck = itemCheck
234 def validate(self, instance):
235 """Validate the field's value (for internal use only).
237 Parameters
238 ----------
239 instance : `lsst.pex.config.Config`
240 The configuration that contains this field.
242 Returns
243 -------
244 isValid : `bool`
245 `True` is returned if the field passes validation criteria (see
246 *Notes*). Otherwise `False`.
248 Notes
249 -----
250 This method validates values according to the following criteria:
252 - A non-optional field is not `None`.
253 - If a value is not `None`, is must pass the `ConfigField.dictCheck`
254 user callback functon.
256 Individual item checks by the `ConfigField.itemCheck` user callback
257 function are done immediately when the value is set on a key. Those
258 checks are not repeated by this method.
259 """
260 Field.validate(self, instance)
261 value = self.__get__(instance)
262 if value is not None and self.dictCheck is not None \
263 and not self.dictCheck(value):
264 msg = "%s is not a valid value" % str(value)
265 raise FieldValidationError(self, instance, msg)
267 def __set__(self, instance, value, at=None, label="assignment"):
268 if instance._frozen:
269 msg = "Cannot modify a frozen Config. "\
270 "Attempting to set field to value %s" % value
271 raise FieldValidationError(self, instance, msg)
273 if at is None:
274 at = getCallStack()
275 if value is not None:
276 value = self.DictClass(instance, self, value, at=at, label=label)
277 else:
278 history = instance._history.setdefault(self.name, [])
279 history.append((value, at, label))
281 instance._storage[self.name] = value
283 def toDict(self, instance):
284 """Convert this field's key-value pairs into a regular `dict`.
286 Parameters
287 ----------
288 instance : `lsst.pex.config.Config`
289 The configuration that contains this field.
291 Returns
292 -------
293 result : `dict` or `None`
294 If this field has a value of `None`, then this method returns
295 `None`. Otherwise, this method returns the field's value as a
296 regular Python `dict`.
297 """
298 value = self.__get__(instance)
299 return dict(value) if value is not None else None
301 def _compare(self, instance1, instance2, shortcut, rtol, atol, output):
302 """Compare two fields for equality.
304 Used by `lsst.pex.ConfigDictField.compare`.
306 Parameters
307 ----------
308 instance1 : `lsst.pex.config.Config`
309 Left-hand side config instance to compare.
310 instance2 : `lsst.pex.config.Config`
311 Right-hand side config instance to compare.
312 shortcut : `bool`
313 If `True`, this function returns as soon as an inequality if found.
314 rtol : `float`
315 Relative tolerance for floating point comparisons.
316 atol : `float`
317 Absolute tolerance for floating point comparisons.
318 output : callable
319 A callable that takes a string, used (possibly repeatedly) to
320 report inequalities.
322 Returns
323 -------
324 isEqual : bool
325 `True` if the fields are equal, `False` otherwise.
327 Notes
328 -----
329 Floating point comparisons are performed by `numpy.allclose`.
330 """
331 d1 = getattr(instance1, self.name)
332 d2 = getattr(instance2, self.name)
333 name = getComparisonName(
334 _joinNamePath(instance1._name, self.name),
335 _joinNamePath(instance2._name, self.name)
336 )
337 if not compareScalars("isnone for %s" % name, d1 is None, d2 is None, output=output):
338 return False
339 if d1 is None and d2 is None:
340 return True
341 if not compareScalars("keys for %s" % name, set(d1.keys()), set(d2.keys()), output=output):
342 return False
343 equal = True
344 for k, v1 in d1.items():
345 v2 = d2[k]
346 result = compareScalars("%s[%r]" % (name, k), v1, v2, dtype=self.itemtype,
347 rtol=rtol, atol=atol, output=output)
348 if not result and shortcut:
349 return False
350 equal = equal and result
351 return equal