Coverage for python/lsst/pex/config/config.py: 60%
394 statements
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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__ = ("Config", "ConfigMeta", "Field", "FieldValidationError")
30import io
31import importlib
32import os
33import re
34import sys
35import math
36import copy
37import tempfile
38import shutil
39import warnings
41# if YAML is not available that's fine and we simply don't register
42# the yaml representer since we know it won't be used.
43try:
44 import yaml
45except ImportError:
46 yaml = None
47 YamlLoaders = ()
48 doImport = None
50from .comparison import getComparisonName, compareScalars, compareConfigs
51from .callStack import getStackFrame, getCallStack
53if yaml: 53 ↛ 64line 53 didn't jump to line 64, because the condition on line 53 was never false
54 YamlLoaders = (yaml.Loader, yaml.FullLoader, yaml.SafeLoader, yaml.UnsafeLoader)
56 try:
57 # CLoader is not always available
58 from yaml import CLoader
59 YamlLoaders += (CLoader,)
60 except ImportError:
61 pass
64def _joinNamePath(prefix=None, name=None, index=None):
65 """Generate nested configuration names.
66 """
67 if not prefix and not name: 67 ↛ 68line 67 didn't jump to line 68, because the condition on line 67 was never true
68 raise ValueError("Invalid name: cannot be None")
69 elif not name: 69 ↛ 70line 69 didn't jump to line 70, because the condition on line 69 was never true
70 name = prefix
71 elif prefix and name: 71 ↛ 74line 71 didn't jump to line 74, because the condition on line 71 was never false
72 name = prefix + "." + name
74 if index is not None: 74 ↛ 75line 74 didn't jump to line 75, because the condition on line 74 was never true
75 return "%s[%r]" % (name, index)
76 else:
77 return name
80def _autocast(x, dtype):
81 """Cast a value to a type, if appropriate.
83 Parameters
84 ----------
85 x : object
86 A value.
87 dtype : tpye
88 Data type, such as `float`, `int`, or `str`.
90 Returns
91 -------
92 values : object
93 If appropriate, the returned value is ``x`` cast to the given type
94 ``dtype``. If the cast cannot be performed the original value of
95 ``x`` is returned.
96 """
97 if dtype == float and isinstance(x, int):
98 return float(x)
99 return x
102def _typeStr(x):
103 """Generate a fully-qualified type name.
105 Returns
106 -------
107 `str`
108 Fully-qualified type name.
110 Notes
111 -----
112 This function is used primarily for writing config files to be executed
113 later upon with the 'load' function.
114 """
115 if hasattr(x, '__module__') and hasattr(x, '__name__'):
116 xtype = x
117 else:
118 xtype = type(x)
119 if (sys.version_info.major <= 2 and xtype.__module__ == '__builtin__') or xtype.__module__ == 'builtins': 119 ↛ 120line 119 didn't jump to line 120, because the condition on line 119 was never true
120 return xtype.__name__
121 else:
122 return "%s.%s" % (xtype.__module__, xtype.__name__)
125if yaml: 125 ↛ 157line 125 didn't jump to line 157, because the condition on line 125 was never false
126 def _yaml_config_representer(dumper, data):
127 """Represent a Config object in a form suitable for YAML.
129 Stores the serialized stream as a scalar block string.
130 """
131 stream = io.StringIO()
132 data.saveToStream(stream)
133 config_py = stream.getvalue()
135 # Strip multiple newlines from the end of the config
136 # This simplifies the YAML to use | and not |+
137 config_py = config_py.rstrip() + "\n"
139 # Trailing spaces force pyyaml to use non-block form.
140 # Remove the trailing spaces so it has no choice
141 config_py = re.sub(r"\s+$", "\n", config_py, flags=re.MULTILINE)
143 # Store the Python as a simple scalar
144 return dumper.represent_scalar("lsst.pex.config.Config", config_py, style="|")
146 def _yaml_config_constructor(loader, node):
147 """Construct a config from YAML"""
148 config_py = loader.construct_scalar(node)
149 return Config._fromPython(config_py)
151 # Register a generic constructor for Config and all subclasses
152 # Need to register for all the loaders we would like to use
153 for loader in YamlLoaders:
154 yaml.add_constructor("lsst.pex.config.Config", _yaml_config_constructor, Loader=loader)
157class ConfigMeta(type):
158 """A metaclass for `lsst.pex.config.Config`.
160 Notes
161 -----
162 ``ConfigMeta`` adds a dictionary containing all `~lsst.pex.config.Field`
163 class attributes as a class attribute called ``_fields``, and adds
164 the name of each field as an instance variable of the field itself (so you
165 don't have to pass the name of the field to the field constructor).
166 """
168 def __init__(cls, name, bases, dict_):
169 type.__init__(cls, name, bases, dict_)
170 cls._fields = {}
171 cls._source = getStackFrame()
173 def getFields(classtype):
174 fields = {}
175 bases = list(classtype.__bases__)
176 bases.reverse()
177 for b in bases:
178 fields.update(getFields(b))
180 for k, v in classtype.__dict__.items():
181 if isinstance(v, Field):
182 fields[k] = v
183 return fields
185 fields = getFields(cls)
186 for k, v in fields.items():
187 setattr(cls, k, copy.deepcopy(v))
189 def __setattr__(cls, name, value):
190 if isinstance(value, Field):
191 value.name = name
192 cls._fields[name] = value
193 type.__setattr__(cls, name, value)
196class FieldValidationError(ValueError):
197 """Raised when a ``~lsst.pex.config.Field`` is not valid in a
198 particular ``~lsst.pex.config.Config``.
200 Parameters
201 ----------
202 field : `lsst.pex.config.Field`
203 The field that was not valid.
204 config : `lsst.pex.config.Config`
205 The config containing the invalid field.
206 msg : `str`
207 Text describing why the field was not valid.
208 """
210 def __init__(self, field, config, msg):
211 self.fieldType = type(field)
212 """Type of the `~lsst.pex.config.Field` that incurred the error.
213 """
215 self.fieldName = field.name
216 """Name of the `~lsst.pex.config.Field` instance that incurred the
217 error (`str`).
219 See also
220 --------
221 lsst.pex.config.Field.name
222 """
224 self.fullname = _joinNamePath(config._name, field.name)
225 """Fully-qualified name of the `~lsst.pex.config.Field` instance
226 (`str`).
227 """
229 self.history = config.history.setdefault(field.name, [])
230 """Full history of all changes to the `~lsst.pex.config.Field`
231 instance.
232 """
234 self.fieldSource = field.source
235 """File and line number of the `~lsst.pex.config.Field` definition.
236 """
238 self.configSource = config._source
239 error = "%s '%s' failed validation: %s\n"\
240 "For more information see the Field definition at:\n%s"\
241 " and the Config definition at:\n%s" % \
242 (self.fieldType.__name__, self.fullname, msg,
243 self.fieldSource.format(), self.configSource.format())
244 super().__init__(error)
247class Field:
248 """A field in a `~lsst.pex.config.Config` that supports `int`, `float`,
249 `complex`, `bool`, and `str` data types.
251 Parameters
252 ----------
253 doc : `str`
254 A description of the field for users.
255 dtype : type
256 The field's data type. ``Field`` only supports basic data types:
257 `int`, `float`, `complex`, `bool`, and `str`. See
258 `Field.supportedTypes`.
259 default : object, optional
260 The field's default value.
261 check : callable, optional
262 A callable that is called with the field's value. This callable should
263 return `False` if the value is invalid. More complex inter-field
264 validation can be written as part of the
265 `lsst.pex.config.Config.validate` method.
266 optional : `bool`, optional
267 This sets whether the field is considered optional, and therefore
268 doesn't need to be set by the user. When `False`,
269 `lsst.pex.config.Config.validate` fails if the field's value is `None`.
270 deprecated : None or `str`, optional
271 A description of why this Field is deprecated, including removal date.
272 If not None, the string is appended to the docstring for this Field.
274 Raises
275 ------
276 ValueError
277 Raised when the ``dtype`` parameter is not one of the supported types
278 (see `Field.supportedTypes`).
280 See also
281 --------
282 ChoiceField
283 ConfigChoiceField
284 ConfigDictField
285 ConfigField
286 ConfigurableField
287 DictField
288 ListField
289 RangeField
290 RegistryField
292 Notes
293 -----
294 ``Field`` instances (including those of any subclass of ``Field``) are used
295 as class attributes of `~lsst.pex.config.Config` subclasses (see the
296 example, below). ``Field`` attributes work like the `property` attributes
297 of classes that implement custom setters and getters. `Field` attributes
298 belong to the class, but operate on the instance. Formally speaking,
299 `Field` attributes are `descriptors
300 <https://docs.python.org/3/howto/descriptor.html>`_.
302 When you access a `Field` attribute on a `Config` instance, you don't
303 get the `Field` instance itself. Instead, you get the value of that field,
304 which might be a simple type (`int`, `float`, `str`, `bool`) or a custom
305 container type (like a `lsst.pex.config.List`) depending on the field's
306 type. See the example, below.
308 Examples
309 --------
310 Instances of ``Field`` should be used as class attributes of
311 `lsst.pex.config.Config` subclasses:
313 >>> from lsst.pex.config import Config, Field
314 >>> class Example(Config):
315 ... myInt = Field("An integer field.", int, default=0)
316 ...
317 >>> print(config.myInt)
318 0
319 >>> config.myInt = 5
320 >>> print(config.myInt)
321 5
322 """
324 supportedTypes = set((str, bool, float, int, complex))
325 """Supported data types for field values (`set` of types).
326 """
328 def __init__(self, doc, dtype, default=None, check=None, optional=False, deprecated=None):
329 if dtype not in self.supportedTypes: 329 ↛ 330line 329 didn't jump to line 330, because the condition on line 329 was never true
330 raise ValueError("Unsupported Field dtype %s" % _typeStr(dtype))
332 source = getStackFrame()
333 self._setup(doc=doc, dtype=dtype, default=default, check=check, optional=optional, source=source,
334 deprecated=deprecated)
336 def _setup(self, doc, dtype, default, check, optional, source, deprecated):
337 """Set attributes, usually during initialization.
338 """
339 self.dtype = dtype
340 """Data type for the field.
341 """
343 # append the deprecation message to the docstring.
344 if deprecated is not None:
345 doc = f"{doc} Deprecated: {deprecated}"
346 self.doc = doc
347 """A description of the field (`str`).
348 """
350 self.deprecated = deprecated
351 """If not None, a description of why this field is deprecated (`str`).
352 """
354 self.__doc__ = f"{doc} (`{dtype.__name__}`"
355 if optional or default is not None:
356 self.__doc__ += f", default ``{default!r}``"
357 self.__doc__ += ")"
359 self.default = default
360 """Default value for this field.
361 """
363 self.check = check
364 """A user-defined function that validates the value of the field.
365 """
367 self.optional = optional
368 """Flag that determines if the field is required to be set (`bool`).
370 When `False`, `lsst.pex.config.Config.validate` will fail if the
371 field's value is `None`.
372 """
374 self.source = source
375 """The stack frame where this field is defined (`list` of
376 `lsst.pex.config.callStack.StackFrame`).
377 """
379 def rename(self, instance):
380 """Rename the field in a `~lsst.pex.config.Config` (for internal use
381 only).
383 Parameters
384 ----------
385 instance : `lsst.pex.config.Config`
386 The config instance that contains this field.
388 Notes
389 -----
390 This method is invoked by the `lsst.pex.config.Config` object that
391 contains this field and should not be called directly.
393 Renaming is only relevant for `~lsst.pex.config.Field` instances that
394 hold subconfigs. `~lsst.pex.config.Fields` that hold subconfigs should
395 rename each subconfig with the full field name as generated by
396 `lsst.pex.config.config._joinNamePath`.
397 """
398 pass
400 def validate(self, instance):
401 """Validate the field (for internal use only).
403 Parameters
404 ----------
405 instance : `lsst.pex.config.Config`
406 The config instance that contains this field.
408 Raises
409 ------
410 lsst.pex.config.FieldValidationError
411 Raised if verification fails.
413 Notes
414 -----
415 This method provides basic validation:
417 - Ensures that the value is not `None` if the field is not optional.
418 - Ensures type correctness.
419 - Ensures that the user-provided ``check`` function is valid.
421 Most `~lsst.pex.config.Field` subclasses should call
422 `lsst.pex.config.field.Field.validate` if they re-implement
423 `~lsst.pex.config.field.Field.validate`.
424 """
425 value = self.__get__(instance)
426 if not self.optional and value is None:
427 raise FieldValidationError(self, instance, "Required value cannot be None")
429 def freeze(self, instance):
430 """Make this field read-only (for internal use only).
432 Parameters
433 ----------
434 instance : `lsst.pex.config.Config`
435 The config instance that contains this field.
437 Notes
438 -----
439 Freezing is only relevant for fields that hold subconfigs. Fields which
440 hold subconfigs should freeze each subconfig.
442 **Subclasses should implement this method.**
443 """
444 pass
446 def _validateValue(self, value):
447 """Validate a value.
449 Parameters
450 ----------
451 value : object
452 The value being validated.
454 Raises
455 ------
456 TypeError
457 Raised if the value's type is incompatible with the field's
458 ``dtype``.
459 ValueError
460 Raised if the value is rejected by the ``check`` method.
461 """
462 if value is None: 462 ↛ 463line 462 didn't jump to line 463, because the condition on line 462 was never true
463 return
465 if not isinstance(value, self.dtype): 465 ↛ 466line 465 didn't jump to line 466, because the condition on line 465 was never true
466 msg = "Value %s is of incorrect type %s. Expected type %s" % \
467 (value, _typeStr(value), _typeStr(self.dtype))
468 raise TypeError(msg)
469 if self.check is not None and not self.check(value): 469 ↛ 470line 469 didn't jump to line 470, because the condition on line 469 was never true
470 msg = "Value %s is not a valid value" % str(value)
471 raise ValueError(msg)
473 def _collectImports(self, instance, imports):
474 """This function should call the _collectImports method on all config
475 objects the field may own, and union them with the supplied imports
476 set.
478 Parameters
479 ----------
480 instance : instance or subclass of `lsst.pex.config.Config`
481 A config object that has this field defined on it
482 imports : `set`
483 Set of python modules that need imported after persistence
484 """
485 pass
487 def save(self, outfile, instance):
488 """Save this field to a file (for internal use only).
490 Parameters
491 ----------
492 outfile : file-like object
493 A writeable field handle.
494 instance : `Config`
495 The `Config` instance that contains this field.
497 Notes
498 -----
499 This method is invoked by the `~lsst.pex.config.Config` object that
500 contains this field and should not be called directly.
502 The output consists of the documentation string
503 (`lsst.pex.config.Field.doc`) formatted as a Python comment. The second
504 line is formatted as an assignment: ``{fullname}={value}``.
506 This output can be executed with Python.
507 """
508 value = self.__get__(instance)
509 fullname = _joinNamePath(instance._name, self.name)
511 if self.deprecated and value == self.default: 511 ↛ 512line 511 didn't jump to line 512, because the condition on line 511 was never true
512 return
514 # write full documentation string as comment lines
515 # (i.e. first character is #)
516 doc = "# " + str(self.doc).replace("\n", "\n# ")
517 if isinstance(value, float) and not math.isfinite(value): 517 ↛ 519line 517 didn't jump to line 519, because the condition on line 517 was never true
518 # non-finite numbers need special care
519 outfile.write(u"{}\n{}=float('{!r}')\n\n".format(doc, fullname, value))
520 else:
521 outfile.write(u"{}\n{}={!r}\n\n".format(doc, fullname, value))
523 def toDict(self, instance):
524 """Convert the field value so that it can be set as the value of an
525 item in a `dict` (for internal use only).
527 Parameters
528 ----------
529 instance : `Config`
530 The `Config` that contains this field.
532 Returns
533 -------
534 value : object
535 The field's value. See *Notes*.
537 Notes
538 -----
539 This method invoked by the owning `~lsst.pex.config.Config` object and
540 should not be called directly.
542 Simple values are passed through. Complex data structures must be
543 manipulated. For example, a `~lsst.pex.config.Field` holding a
544 subconfig should, instead of the subconfig object, return a `dict`
545 where the keys are the field names in the subconfig, and the values are
546 the field values in the subconfig.
547 """
548 return self.__get__(instance)
550 def __get__(self, instance, owner=None, at=None, label="default"):
551 """Define how attribute access should occur on the Config instance
552 This is invoked by the owning config object and should not be called
553 directly
555 When the field attribute is accessed on a Config class object, it
556 returns the field object itself in order to allow inspection of
557 Config classes.
559 When the field attribute is access on a config instance, the actual
560 value described by the field (and held by the Config instance) is
561 returned.
562 """
563 if instance is None or not isinstance(instance, Config): 563 ↛ 564line 563 didn't jump to line 564, because the condition on line 563 was never true
564 return self
565 else:
566 return instance._storage[self.name]
568 def __set__(self, instance, value, at=None, label='assignment'):
569 """Set an attribute on the config instance.
571 Parameters
572 ----------
573 instance : `lsst.pex.config.Config`
574 The config instance that contains this field.
575 value : obj
576 Value to set on this field.
577 at : `list` of `lsst.pex.config.callStack.StackFrame`
578 The call stack (created by
579 `lsst.pex.config.callStack.getCallStack`).
580 label : `str`, optional
581 Event label for the history.
583 Notes
584 -----
585 This method is invoked by the owning `lsst.pex.config.Config` object
586 and should not be called directly.
588 Derived `~lsst.pex.config.Field` classes may need to override the
589 behavior. When overriding ``__set__``, `~lsst.pex.config.Field` authors
590 should follow the following rules:
592 - Do not allow modification of frozen configs.
593 - Validate the new value **before** modifying the field. Except if the
594 new value is `None`. `None` is special and no attempt should be made
595 to validate it until `lsst.pex.config.Config.validate` is called.
596 - Do not modify the `~lsst.pex.config.Config` instance to contain
597 invalid values.
598 - If the field is modified, update the history of the
599 `lsst.pex.config.field.Field` to reflect the changes.
601 In order to decrease the need to implement this method in derived
602 `~lsst.pex.config.Field` types, value validation is performed in the
603 `lsst.pex.config.Field._validateValue`. If only the validation step
604 differs in the derived `~lsst.pex.config.Field`, it is simpler to
605 implement `lsst.pex.config.Field._validateValue` than to reimplement
606 ``__set__``. More complicated behavior, however, may require
607 reimplementation.
608 """
609 if instance._frozen: 609 ↛ 610line 609 didn't jump to line 610, because the condition on line 609 was never true
610 raise FieldValidationError(self, instance, "Cannot modify a frozen Config")
612 history = instance._history.setdefault(self.name, [])
613 if value is not None: 613 ↛ 620line 613 didn't jump to line 620, because the condition on line 613 was never false
614 value = _autocast(value, self.dtype)
615 try:
616 self._validateValue(value)
617 except BaseException as e:
618 raise FieldValidationError(self, instance, str(e))
620 instance._storage[self.name] = value
621 if at is None: 621 ↛ 622line 621 didn't jump to line 622, because the condition on line 621 was never true
622 at = getCallStack()
623 history.append((value, at, label))
625 def __delete__(self, instance, at=None, label='deletion'):
626 """Delete an attribute from a `lsst.pex.config.Config` instance.
628 Parameters
629 ----------
630 instance : `lsst.pex.config.Config`
631 The config instance that contains this field.
632 at : `list` of `lsst.pex.config.callStack.StackFrame`
633 The call stack (created by
634 `lsst.pex.config.callStack.getCallStack`).
635 label : `str`, optional
636 Event label for the history.
638 Notes
639 -----
640 This is invoked by the owning `~lsst.pex.config.Config` object and
641 should not be called directly.
642 """
643 if at is None:
644 at = getCallStack()
645 self.__set__(instance, None, at=at, label=label)
647 def _compare(self, instance1, instance2, shortcut, rtol, atol, output):
648 """Compare a field (named `Field.name`) in two
649 `~lsst.pex.config.Config` instances for equality.
651 Parameters
652 ----------
653 instance1 : `lsst.pex.config.Config`
654 Left-hand side `Config` instance to compare.
655 instance2 : `lsst.pex.config.Config`
656 Right-hand side `Config` instance to compare.
657 shortcut : `bool`, optional
658 **Unused.**
659 rtol : `float`, optional
660 Relative tolerance for floating point comparisons.
661 atol : `float`, optional
662 Absolute tolerance for floating point comparisons.
663 output : callable, optional
664 A callable that takes a string, used (possibly repeatedly) to
665 report inequalities.
667 Notes
668 -----
669 This method must be overridden by more complex `Field` subclasses.
671 See also
672 --------
673 lsst.pex.config.compareScalars
674 """
675 v1 = getattr(instance1, self.name)
676 v2 = getattr(instance2, self.name)
677 name = getComparisonName(
678 _joinNamePath(instance1._name, self.name),
679 _joinNamePath(instance2._name, self.name)
680 )
681 return compareScalars(name, v1, v2, dtype=self.dtype, rtol=rtol, atol=atol, output=output)
684class RecordingImporter:
685 """Importer (for `sys.meta_path`) that records which modules are being
686 imported.
688 *This class does not do any importing itself.*
690 Examples
691 --------
692 Use this class as a context manager to ensure it is properly uninstalled
693 when done:
695 >>> with RecordingImporter() as importer:
696 ... # import stuff
697 ... import numpy as np
698 ... print("Imported: " + importer.getModules())
699 """
701 def __init__(self):
702 self._modules = set()
704 def __enter__(self):
705 self.origMetaPath = sys.meta_path
706 sys.meta_path = [self] + sys.meta_path
707 return self
709 def __exit__(self, *args):
710 self.uninstall()
711 return False # Don't suppress exceptions
713 def uninstall(self):
714 """Uninstall the importer.
715 """
716 sys.meta_path = self.origMetaPath
718 def find_module(self, fullname, path=None):
719 """Called as part of the ``import`` chain of events.
720 """
721 self._modules.add(fullname)
722 # Return None because we don't do any importing.
723 return None
725 def getModules(self):
726 """Get the set of modules that were imported.
728 Returns
729 -------
730 modules : `set` of `str`
731 Set of imported module names.
732 """
733 return self._modules
736class Config(metaclass=ConfigMeta):
737 """Base class for configuration (*config*) objects.
739 Notes
740 -----
741 A ``Config`` object will usually have several `~lsst.pex.config.Field`
742 instances as class attributes. These are used to define most of the base
743 class behavior.
745 ``Config`` implements a mapping API that provides many `dict`-like methods,
746 such as `keys`, `values`, `items`, `iteritems`, `iterkeys`, and
747 `itervalues`. ``Config`` instances also support the ``in`` operator to
748 test if a field is in the config. Unlike a `dict`, ``Config`` classes are
749 not subscriptable. Instead, access individual fields as attributes of the
750 configuration instance.
752 Examples
753 --------
754 Config classes are subclasses of ``Config`` that have
755 `~lsst.pex.config.Field` instances (or instances of
756 `~lsst.pex.config.Field` subclasses) as class attributes:
758 >>> from lsst.pex.config import Config, Field, ListField
759 >>> class DemoConfig(Config):
760 ... intField = Field(doc="An integer field", dtype=int, default=42)
761 ... listField = ListField(doc="List of favorite beverages.", dtype=str,
762 ... default=['coffee', 'green tea', 'water'])
763 ...
764 >>> config = DemoConfig()
766 Configs support many `dict`-like APIs:
768 >>> config.keys()
769 ['intField', 'listField']
770 >>> 'intField' in config
771 True
773 Individual fields can be accessed as attributes of the configuration:
775 >>> config.intField
776 42
777 >>> config.listField.append('earl grey tea')
778 >>> print(config.listField)
779 ['coffee', 'green tea', 'water', 'earl grey tea']
780 """
782 def __iter__(self):
783 """Iterate over fields.
784 """
785 return self._fields.__iter__()
787 def keys(self):
788 """Get field names.
790 Returns
791 -------
792 names : `list`
793 List of `lsst.pex.config.Field` names.
795 See also
796 --------
797 lsst.pex.config.Config.iterkeys
798 """
799 return list(self._storage.keys())
801 def values(self):
802 """Get field values.
804 Returns
805 -------
806 values : `list`
807 List of field values.
809 See also
810 --------
811 lsst.pex.config.Config.itervalues
812 """
813 return list(self._storage.values())
815 def items(self):
816 """Get configurations as ``(field name, field value)`` pairs.
818 Returns
819 -------
820 items : `list`
821 List of tuples for each configuration. Tuple items are:
823 0. Field name.
824 1. Field value.
826 See also
827 --------
828 lsst.pex.config.Config.iteritems
829 """
830 return list(self._storage.items())
832 def iteritems(self):
833 """Iterate over (field name, field value) pairs.
835 Yields
836 ------
837 item : `tuple`
838 Tuple items are:
840 0. Field name.
841 1. Field value.
843 See also
844 --------
845 lsst.pex.config.Config.items
846 """
847 return iter(self._storage.items())
849 def itervalues(self):
850 """Iterate over field values.
852 Yields
853 ------
854 value : obj
855 A field value.
857 See also
858 --------
859 lsst.pex.config.Config.values
860 """
861 return iter(self.storage.values())
863 def iterkeys(self):
864 """Iterate over field names
866 Yields
867 ------
868 key : `str`
869 A field's key (attribute name).
871 See also
872 --------
873 lsst.pex.config.Config.values
874 """
875 return iter(self.storage.keys())
877 def __contains__(self, name):
878 """!Return True if the specified field exists in this config
880 @param[in] name field name to test for
881 """
882 return self._storage.__contains__(name)
884 def __new__(cls, *args, **kw):
885 """Allocate a new `lsst.pex.config.Config` object.
887 In order to ensure that all Config object are always in a proper state
888 when handed to users or to derived `~lsst.pex.config.Config` classes,
889 some attributes are handled at allocation time rather than at
890 initialization.
892 This ensures that even if a derived `~lsst.pex.config.Config` class
893 implements ``__init__``, its author does not need to be concerned about
894 when or even the base ``Config.__init__`` should be called.
895 """
896 name = kw.pop("__name", None)
897 at = kw.pop("__at", getCallStack())
898 # remove __label and ignore it
899 kw.pop("__label", "default")
901 instance = object.__new__(cls)
902 instance._frozen = False
903 instance._name = name
904 instance._storage = {}
905 instance._history = {}
906 instance._imports = set()
907 # load up defaults
908 for field in instance._fields.values():
909 instance._history[field.name] = []
910 field.__set__(instance, field.default, at=at + [field.source], label="default")
911 # set custom default-overides
912 instance.setDefaults()
913 # set constructor overides
914 instance.update(__at=at, **kw)
915 return instance
917 def __reduce__(self):
918 """Reduction for pickling (function with arguments to reproduce).
920 We need to condense and reconstitute the `~lsst.pex.config.Config`,
921 since it may contain lambdas (as the ``check`` elements) that cannot
922 be pickled.
923 """
924 # The stream must be in characters to match the API but pickle
925 # requires bytes
926 stream = io.StringIO()
927 self.saveToStream(stream)
928 return (unreduceConfig, (self.__class__, stream.getvalue().encode()))
930 def setDefaults(self):
931 """Subclass hook for computing defaults.
933 Notes
934 -----
935 Derived `~lsst.pex.config.Config` classes that must compute defaults
936 rather than using the `~lsst.pex.config.Field` instances's defaults
937 should do so here. To correctly use inherited defaults,
938 implementations of ``setDefaults`` must call their base class's
939 ``setDefaults``.
940 """
941 pass
943 def update(self, **kw):
944 """Update values of fields specified by the keyword arguments.
946 Parameters
947 ----------
948 kw
949 Keywords are configuration field names. Values are configuration
950 field values.
952 Notes
953 -----
954 The ``__at`` and ``__label`` keyword arguments are special internal
955 keywords. They are used to strip out any internal steps from the
956 history tracebacks of the config. Do not modify these keywords to
957 subvert a `~lsst.pex.config.Config` instance's history.
959 Examples
960 --------
961 This is a config with three fields:
963 >>> from lsst.pex.config import Config, Field
964 >>> class DemoConfig(Config):
965 ... fieldA = Field(doc='Field A', dtype=int, default=42)
966 ... fieldB = Field(doc='Field B', dtype=bool, default=True)
967 ... fieldC = Field(doc='Field C', dtype=str, default='Hello world')
968 ...
969 >>> config = DemoConfig()
971 These are the default values of each field:
973 >>> for name, value in config.iteritems():
974 ... print(f"{name}: {value}")
975 ...
976 fieldA: 42
977 fieldB: True
978 fieldC: 'Hello world'
980 Using this method to update ``fieldA`` and ``fieldC``:
982 >>> config.update(fieldA=13, fieldC='Updated!')
984 Now the values of each field are:
986 >>> for name, value in config.iteritems():
987 ... print(f"{name}: {value}")
988 ...
989 fieldA: 13
990 fieldB: True
991 fieldC: 'Updated!'
992 """
993 at = kw.pop("__at", getCallStack())
994 label = kw.pop("__label", "update")
996 for name, value in kw.items():
997 try:
998 field = self._fields[name]
999 field.__set__(self, value, at=at, label=label)
1000 except KeyError:
1001 raise KeyError("No field of name %s exists in config type %s" % (name, _typeStr(self)))
1003 def load(self, filename, root="config"):
1004 """Modify this config in place by executing the Python code in a
1005 configuration file.
1007 Parameters
1008 ----------
1009 filename : `str`
1010 Name of the configuration file. A configuration file is Python
1011 module.
1012 root : `str`, optional
1013 Name of the variable in file that refers to the config being
1014 overridden.
1016 For example, the value of root is ``"config"`` and the file
1017 contains::
1019 config.myField = 5
1021 Then this config's field ``myField`` is set to ``5``.
1023 **Deprecated:** For backwards compatibility, older config files
1024 that use ``root="root"`` instead of ``root="config"`` will be
1025 loaded with a warning printed to `sys.stderr`. This feature will be
1026 removed at some point.
1028 See also
1029 --------
1030 lsst.pex.config.Config.loadFromStream
1031 lsst.pex.config.Config.save
1032 lsst.pex.config.Config.saveFromStream
1033 """
1034 with open(filename, "r") as f:
1035 code = compile(f.read(), filename=filename, mode="exec")
1036 self.loadFromStream(stream=code, root=root, filename=filename)
1038 def loadFromStream(self, stream, root="config", filename=None):
1039 """Modify this Config in place by executing the Python code in the
1040 provided stream.
1042 Parameters
1043 ----------
1044 stream : file-like object, `str`, or compiled string
1045 Stream containing configuration override code.
1046 root : `str`, optional
1047 Name of the variable in file that refers to the config being
1048 overridden.
1050 For example, the value of root is ``"config"`` and the file
1051 contains::
1053 config.myField = 5
1055 Then this config's field ``myField`` is set to ``5``.
1057 **Deprecated:** For backwards compatibility, older config files
1058 that use ``root="root"`` instead of ``root="config"`` will be
1059 loaded with a warning printed to `sys.stderr`. This feature will be
1060 removed at some point.
1061 filename : `str`, optional
1062 Name of the configuration file, or `None` if unknown or contained
1063 in the stream. Used for error reporting.
1065 See also
1066 --------
1067 lsst.pex.config.Config.load
1068 lsst.pex.config.Config.save
1069 lsst.pex.config.Config.saveFromStream
1070 """
1071 with RecordingImporter() as importer:
1072 globals = {"__file__": filename}
1073 try:
1074 local = {root: self}
1075 exec(stream, globals, local)
1076 except NameError as e:
1077 if root == "config" and "root" in e.args[0]:
1078 if filename is None:
1079 # try to determine the file name; a compiled string
1080 # has attribute "co_filename",
1081 # an open file has attribute "name", else give up
1082 filename = getattr(stream, "co_filename", None)
1083 if filename is None:
1084 filename = getattr(stream, "name", "?")
1085 print(f"Config override file {filename!r}"
1086 " appears to use 'root' instead of 'config'; trying with 'root'", file=sys.stderr)
1087 local = {"root": self}
1088 exec(stream, globals, local)
1089 else:
1090 raise
1092 self._imports.update(importer.getModules())
1094 def save(self, filename, root="config"):
1095 """Save a Python script to the named file, which, when loaded,
1096 reproduces this config.
1098 Parameters
1099 ----------
1100 filename : `str`
1101 Desination filename of this configuration.
1102 root : `str`, optional
1103 Name to use for the root config variable. The same value must be
1104 used when loading (see `lsst.pex.config.Config.load`).
1106 See also
1107 --------
1108 lsst.pex.config.Config.saveToStream
1109 lsst.pex.config.Config.load
1110 lsst.pex.config.Config.loadFromStream
1111 """
1112 d = os.path.dirname(filename)
1113 with tempfile.NamedTemporaryFile(mode="w", delete=False, dir=d) as outfile:
1114 self.saveToStream(outfile, root)
1115 # tempfile is hardcoded to create files with mode '0600'
1116 # for an explantion of these antics see:
1117 # https://stackoverflow.com/questions/10291131/how-to-use-os-umask-in-python
1118 umask = os.umask(0o077)
1119 os.umask(umask)
1120 os.chmod(outfile.name, (~umask & 0o666))
1121 # chmod before the move so we get quasi-atomic behavior if the
1122 # source and dest. are on the same filesystem.
1123 # os.rename may not work across filesystems
1124 shutil.move(outfile.name, filename)
1126 def saveToStream(self, outfile, root="config", skipImports=False):
1127 """Save a configuration file to a stream, which, when loaded,
1128 reproduces this config.
1130 Parameters
1131 ----------
1132 outfile : file-like object
1133 Destination file object write the config into. Accepts strings not
1134 bytes.
1135 root
1136 Name to use for the root config variable. The same value must be
1137 used when loading (see `lsst.pex.config.Config.load`).
1138 skipImports : `bool`, optional
1139 If `True` then do not include ``import`` statements in output,
1140 this is to support human-oriented output from ``pipetask`` where
1141 additional clutter is not useful.
1143 See also
1144 --------
1145 lsst.pex.config.Config.save
1146 lsst.pex.config.Config.load
1147 lsst.pex.config.Config.loadFromStream
1148 """
1149 tmp = self._name
1150 self._rename(root)
1151 try:
1152 if not skipImports: 1152 ↛ 1164line 1152 didn't jump to line 1164, because the condition on line 1152 was never false
1153 self._collectImports()
1154 # Remove self from the set, as it is handled explicitly below
1155 self._imports.remove(self.__module__)
1156 configType = type(self)
1157 typeString = _typeStr(configType)
1158 outfile.write(f"import {configType.__module__}\n")
1159 outfile.write(f"assert type({root})=={typeString}, 'config is of type %s.%s instead of "
1160 f"{typeString}' % (type({root}).__module__, type({root}).__name__)\n")
1161 for imp in self._imports: 1161 ↛ 1162line 1161 didn't jump to line 1162, because the loop on line 1161 never started
1162 if imp in sys.modules and sys.modules[imp] is not None:
1163 outfile.write(u"import {}\n".format(imp))
1164 self._save(outfile)
1165 finally:
1166 self._rename(tmp)
1168 def freeze(self):
1169 """Make this config, and all subconfigs, read-only.
1170 """
1171 self._frozen = True
1172 for field in self._fields.values():
1173 field.freeze(self)
1175 def _save(self, outfile):
1176 """Save this config to an open stream object.
1178 Parameters
1179 ----------
1180 outfile : file-like object
1181 Destination file object write the config into. Accepts strings not
1182 bytes.
1183 """
1184 for field in self._fields.values():
1185 field.save(outfile, self)
1187 def _collectImports(self):
1188 """Adds module containing self to the list of things to import and
1189 then loops over all the fields in the config calling a corresponding
1190 collect method. The field method will call _collectImports on any
1191 configs it may own and return the set of things to import. This
1192 returned set will be merged with the set of imports for this config
1193 class.
1194 """
1195 self._imports.add(self.__module__)
1196 for name, field in self._fields.items():
1197 field._collectImports(self, self._imports)
1199 def toDict(self):
1200 """Make a dictionary of field names and their values.
1202 Returns
1203 -------
1204 dict_ : `dict`
1205 Dictionary with keys that are `~lsst.pex.config.Field` names.
1206 Values are `~lsst.pex.config.Field` values.
1208 See also
1209 --------
1210 lsst.pex.config.Field.toDict
1212 Notes
1213 -----
1214 This method uses the `~lsst.pex.config.Field.toDict` method of
1215 individual fields. Subclasses of `~lsst.pex.config.Field` may need to
1216 implement a ``toDict`` method for *this* method to work.
1217 """
1218 dict_ = {}
1219 for name, field in self._fields.items():
1220 dict_[name] = field.toDict(self)
1221 return dict_
1223 def names(self):
1224 """Get all the field names in the config, recursively.
1226 Returns
1227 -------
1228 names : `list` of `str`
1229 Field names.
1230 """
1231 #
1232 # Rather than sort out the recursion all over again use the
1233 # pre-existing saveToStream()
1234 #
1235 with io.StringIO() as strFd:
1236 self.saveToStream(strFd, "config")
1237 contents = strFd.getvalue()
1238 strFd.close()
1239 #
1240 # Pull the names out of the dumped config
1241 #
1242 keys = []
1243 for line in contents.split("\n"):
1244 if re.search(r"^((assert|import)\s+|\s*$|#)", line):
1245 continue
1247 mat = re.search(r"^(?:config\.)?([^=]+)\s*=\s*.*", line)
1248 if mat:
1249 keys.append(mat.group(1))
1251 return keys
1253 def _rename(self, name):
1254 """Rename this config object in its parent `~lsst.pex.config.Config`.
1256 Parameters
1257 ----------
1258 name : `str`
1259 New name for this config in its parent `~lsst.pex.config.Config`.
1261 Notes
1262 -----
1263 This method uses the `~lsst.pex.config.Field.rename` method of
1264 individual `lsst.pex.config.Field` instances.
1265 `lsst.pex.config.Field` subclasses may need to implement a ``rename``
1266 method for *this* method to work.
1268 See also
1269 --------
1270 lsst.pex.config.Field.rename
1271 """
1272 self._name = name
1273 for field in self._fields.values():
1274 field.rename(self)
1276 def validate(self):
1277 """Validate the Config, raising an exception if invalid.
1279 Raises
1280 ------
1281 lsst.pex.config.FieldValidationError
1282 Raised if verification fails.
1284 Notes
1285 -----
1286 The base class implementation performs type checks on all fields by
1287 calling their `~lsst.pex.config.Field.validate` methods.
1289 Complex single-field validation can be defined by deriving new Field
1290 types. For convenience, some derived `lsst.pex.config.Field`-types
1291 (`~lsst.pex.config.ConfigField` and
1292 `~lsst.pex.config.ConfigChoiceField`) are defined in `lsst.pex.config`
1293 that handle recursing into subconfigs.
1295 Inter-field relationships should only be checked in derived
1296 `~lsst.pex.config.Config` classes after calling this method, and base
1297 validation is complete.
1298 """
1299 for field in self._fields.values():
1300 field.validate(self)
1302 def formatHistory(self, name, **kwargs):
1303 """Format a configuration field's history to a human-readable format.
1305 Parameters
1306 ----------
1307 name : `str`
1308 Name of a `~lsst.pex.config.Field` in this config.
1309 kwargs
1310 Keyword arguments passed to `lsst.pex.config.history.format`.
1312 Returns
1313 -------
1314 history : `str`
1315 A string containing the formatted history.
1317 See also
1318 --------
1319 lsst.pex.config.history.format
1320 """
1321 import lsst.pex.config.history as pexHist
1322 return pexHist.format(self, name, **kwargs)
1324 history = property(lambda x: x._history) 1324 ↛ exitline 1324 didn't run the lambda on line 1324
1325 """Read-only history.
1326 """
1328 def __setattr__(self, attr, value, at=None, label="assignment"):
1329 """Set an attribute (such as a field's value).
1331 Notes
1332 -----
1333 Unlike normal Python objects, `~lsst.pex.config.Config` objects are
1334 locked such that no additional attributes nor properties may be added
1335 to them dynamically.
1337 Although this is not the standard Python behavior, it helps to protect
1338 users from accidentally mispelling a field name, or trying to set a
1339 non-existent field.
1340 """
1341 if attr in self._fields:
1342 if self._fields[attr].deprecated is not None: 1342 ↛ 1343line 1342 didn't jump to line 1343, because the condition on line 1342 was never true
1343 fullname = _joinNamePath(self._name, self._fields[attr].name)
1344 warnings.warn(f"Config field {fullname} is deprecated: {self._fields[attr].deprecated}",
1345 FutureWarning, stacklevel=2)
1346 if at is None: 1346 ↛ 1349line 1346 didn't jump to line 1349, because the condition on line 1346 was never false
1347 at = getCallStack()
1348 # This allows Field descriptors to work.
1349 self._fields[attr].__set__(self, value, at=at, label=label)
1350 elif hasattr(getattr(self.__class__, attr, None), '__set__'): 1350 ↛ 1352line 1350 didn't jump to line 1352, because the condition on line 1350 was never true
1351 # This allows properties and other non-Field descriptors to work.
1352 return object.__setattr__(self, attr, value)
1353 elif attr in self.__dict__ or attr in ("_name", "_history", "_storage", "_frozen", "_imports"): 1353 ↛ 1358line 1353 didn't jump to line 1358, because the condition on line 1353 was never false
1354 # This allows specific private attributes to work.
1355 self.__dict__[attr] = value
1356 else:
1357 # We throw everything else.
1358 raise AttributeError("%s has no attribute %s" % (_typeStr(self), attr))
1360 def __delattr__(self, attr, at=None, label="deletion"):
1361 if attr in self._fields:
1362 if at is None:
1363 at = getCallStack()
1364 self._fields[attr].__delete__(self, at=at, label=label)
1365 else:
1366 object.__delattr__(self, attr)
1368 def __eq__(self, other):
1369 if type(other) == type(self): 1369 ↛ 1370line 1369 didn't jump to line 1370, because the condition on line 1369 was never true
1370 for name in self._fields:
1371 thisValue = getattr(self, name)
1372 otherValue = getattr(other, name)
1373 if isinstance(thisValue, float) and math.isnan(thisValue):
1374 if not math.isnan(otherValue):
1375 return False
1376 elif thisValue != otherValue:
1377 return False
1378 return True
1379 return False
1381 def __ne__(self, other):
1382 return not self.__eq__(other)
1384 def __str__(self):
1385 return str(self.toDict())
1387 def __repr__(self):
1388 return "%s(%s)" % (
1389 _typeStr(self),
1390 ", ".join("%s=%r" % (k, v) for k, v in self.toDict().items() if v is not None)
1391 )
1393 def compare(self, other, shortcut=True, rtol=1E-8, atol=1E-8, output=None):
1394 """Compare this configuration to another `~lsst.pex.config.Config` for
1395 equality.
1397 Parameters
1398 ----------
1399 other : `lsst.pex.config.Config`
1400 Other `~lsst.pex.config.Config` object to compare against this
1401 config.
1402 shortcut : `bool`, optional
1403 If `True`, return as soon as an inequality is found. Default is
1404 `True`.
1405 rtol : `float`, optional
1406 Relative tolerance for floating point comparisons.
1407 atol : `float`, optional
1408 Absolute tolerance for floating point comparisons.
1409 output : callable, optional
1410 A callable that takes a string, used (possibly repeatedly) to
1411 report inequalities.
1413 Returns
1414 -------
1415 isEqual : `bool`
1416 `True` when the two `lsst.pex.config.Config` instances are equal.
1417 `False` if there is an inequality.
1419 See also
1420 --------
1421 lsst.pex.config.compareConfigs
1423 Notes
1424 -----
1425 Unselected targets of `~lsst.pex.config.RegistryField` fields and
1426 unselected choices of `~lsst.pex.config.ConfigChoiceField` fields
1427 are not considered by this method.
1429 Floating point comparisons are performed by `numpy.allclose`.
1430 """
1431 name1 = self._name if self._name is not None else "config"
1432 name2 = other._name if other._name is not None else "config"
1433 name = getComparisonName(name1, name2)
1434 return compareConfigs(name, self, other, shortcut=shortcut,
1435 rtol=rtol, atol=atol, output=output)
1437 @classmethod
1438 def __init_subclass__(cls, **kwargs):
1439 """Run initialization for every subclass.
1441 Specifically registers the subclass with a YAML representer
1442 and YAML constructor (if pyyaml is available)
1443 """
1444 super().__init_subclass__(**kwargs)
1446 if not yaml: 1446 ↛ 1447line 1446 didn't jump to line 1447, because the condition on line 1446 was never true
1447 return
1449 yaml.add_representer(cls, _yaml_config_representer)
1451 @classmethod
1452 def _fromPython(cls, config_py):
1453 """Instantiate a `Config`-subclass from serialized Python form.
1455 Parameters
1456 ----------
1457 config_py : `str`
1458 A serialized form of the Config as created by
1459 `Config.saveToStream`.
1461 Returns
1462 -------
1463 config : `Config`
1464 Reconstructed `Config` instant.
1465 """
1466 cls = _classFromPython(config_py)
1467 return unreduceConfig(cls, config_py)
1470def _classFromPython(config_py):
1471 """Return the Config subclass required by this Config serialization.
1473 Parameters
1474 ----------
1475 config_py : `str`
1476 A serialized form of the Config as created by
1477 `Config.saveToStream`.
1479 Returns
1480 -------
1481 cls : `type`
1482 The `Config` subclass associated with this config.
1483 """
1484 # standard serialization has the form:
1485 # import config.class
1486 # assert type(config)==config.class.Config, ...
1487 # We want to parse these two lines so we can get the class itself
1489 # Do a single regex to avoid large string copies when splitting a
1490 # large config into separate lines.
1491 matches = re.search(r"^import ([\w.]+)\nassert .*==(.*?),", config_py)
1493 if not matches:
1494 first_line, second_line, _ = config_py.split("\n", 2)
1495 raise ValueError("First two lines did not match expected form. Got:\n"
1496 f" - {first_line}\n"
1497 f" - {second_line}")
1499 module_name = matches.group(1)
1500 module = importlib.import_module(module_name)
1502 # Second line
1503 full_name = matches.group(2)
1505 # Remove the module name from the full name
1506 if not full_name.startswith(module_name):
1507 raise ValueError(f"Module name ({module_name}) inconsistent with full name ({full_name})")
1509 # if module name is a.b.c and full name is a.b.c.d.E then
1510 # we need to remove a.b.c. and iterate over the remainder
1511 # The +1 is for the extra dot after a.b.c
1512 remainder = full_name[len(module_name)+1:]
1513 components = remainder.split(".")
1514 pytype = module
1515 for component in components:
1516 pytype = getattr(pytype, component)
1517 return pytype
1520def unreduceConfig(cls, stream):
1521 """Create a `~lsst.pex.config.Config` from a stream.
1523 Parameters
1524 ----------
1525 cls : `lsst.pex.config.Config`-type
1526 A `lsst.pex.config.Config` type (not an instance) that is instantiated
1527 with configurations in the ``stream``.
1528 stream : file-like object, `str`, or compiled string
1529 Stream containing configuration override code.
1531 Returns
1532 -------
1533 config : `lsst.pex.config.Config`
1534 Config instance.
1536 See also
1537 --------
1538 lsst.pex.config.Config.loadFromStream
1539 """
1540 config = cls()
1541 config.loadFromStream(stream)
1542 return config