RegistryField

class lsst.pex.config.RegistryField(doc, registry, default=None, optional=False, multi=False, on_none=None)

Bases: ConfigChoiceField

A configuration field whose options are defined in a Registry.

Parameters:

docstr

A description of the field.

registryRegistry

The registry that contains this field.

defaultstr, optional

The default target key.

optionalbool, optional

When False, lsst.pex.config.Config.validate fails if the field’s value is None.

multibool, optional

If True, the field allows multiple selections. The default is False.

on_noneCallable, optional

A callable that should be invoked when apply is called but the selected name or names is None. Will be passed the field attribute proxy (RegistryInstanceDict) and then all positional and keyword arguments passed to apply.

See also

ChoiceField

ConfigChoiceField

ConfigDictField

ConfigField

ConfigurableField

DictField

Field

ListField

RangeField

Attributes Summary

supportedTypes

Supported data types for field values (set of types).

Methods Summary

freeze(instance)	Make this field read-only (for internal use only).
rename(instance)	Rename the field in a Config (for internal use only).
save(outfile, instance)	Save this field to a file (for internal use only).
toDict(instance)	Convert the field value so that it can be set as the value of an item in a dict (for internal use only).
validate(instance)	Validate the field (for internal use only).

Attributes Documentation

supportedTypes = {<class 'bool'>, <class 'complex'>, <class 'float'>, <class 'str'>, <class 'int'>}

Supported data types for field values (set of types).

Methods Documentation

freeze(instance)

Make this field read-only (for internal use only).

Parameters:

instancelsst.pex.config.Config

The config instance that contains this field.

Notes

Freezing is only relevant for fields that hold subconfigs. Fields which hold subconfigs should freeze each subconfig.

Subclasses should implement this method.

rename(instance)

Rename the field in a Config (for internal use only).

Parameters:

instancelsst.pex.config.Config

The config instance that contains this field.

Notes

This method is invoked by the lsst.pex.config.Config object that contains this field and should not be called directly.

Renaming is only relevant for Field instances that hold subconfigs. Fields that hold subconfigs should rename each subconfig with the full field name as generated by lsst.pex.config.config._joinNamePath.

save(outfile, instance)

Save this field to a file (for internal use only).

Parameters:

outfilefile-like object

A writeable field handle.

instanceConfig

The Config instance that contains this field.

Notes

This method is invoked by the Config object that contains this field and should not be called directly.

The output consists of the documentation string (lsst.pex.config.Field.doc) formatted as a Python comment. The second line is formatted as an assignment: {fullname}={value}.

This output can be executed with Python.

toDict(instance)

Convert the field value so that it can be set as the value of an item in a dict (for internal use only).

Parameters:

instanceConfig

The Config that contains this field.

Returns:

valueobject

The field’s value. See Notes.

Notes

This method invoked by the owning Config object and should not be called directly.

Simple values are passed through. Complex data structures must be manipulated. For example, a Field holding a subconfig should, instead of the subconfig object, return a dict where the keys are the field names in the subconfig, and the values are the field values in the subconfig.

validate(instance)

Validate the field (for internal use only).

Parameters:

instancelsst.pex.config.Config

The config instance that contains this field.

Raises:

lsst.pex.config.FieldValidationError

Raised if verification fails.

Notes

This method provides basic validation:

• Ensures that the value is not None if the field is not optional.

• Ensures type correctness.

• Ensures that the user-provided check function is valid.

Most Field subclasses should call lsst.pex.config.Field.validate if they re-implement validate.