pex.config.dictField.DictField Class Reference

Inheritance diagram for pex.config.dictField.DictField:

Public Member Functions
def	__init__ (self, doc, keytype, itemtype, default=None, optional=False, dictCheck=None, itemCheck=None, deprecated=None)
def	validate (self, instance)
def	__set__ (self, instance, value, at=None, label="assignment")
def	toDict (self, instance)
def	rename (self, instance)
def	freeze (self, instance)
def	save (self, outfile, instance)
def	__get__ (self, instance, owner=None, at=None, label="default")
def	__delete__ (self, instance, at=None, label='deletion')

Public Attributes
	keytype
	itemtype
	dictCheck
	itemCheck
	dtype
	doc
	deprecated
	default
	check
	optional
	source

Static Public Attributes
	DictClass = Dict
	supportedTypes = set((str, bool, float, int, complex))

Detailed Description

A configuration field (`~lsst.pex.config.Field` subclass) that maps keys
and values.

The types of both items and keys are restricted to these builtin types:
`int`, `float`, `complex`, `bool`, and `str`). All keys share the same type
and all values share the same type. Keys can have a different type from
values.

Parameters
----------
doc : `str`
    A documentation string that describes the configuration field.
keytype : {`int`, `float`, `complex`, `bool`, `str`}
    The type of the mapping keys. All keys must have this type.
itemtype : {`int`, `float`, `complex`, `bool`, `str`}
    Type of the mapping values.
default : `dict`, optional
    The default mapping.
optional : `bool`, optional
    If `True`, the field doesn't need to have a set value.
dictCheck : callable
    A function that validates the dictionary as a whole.
itemCheck : callable
    A function that validates individual mapping values.
deprecated : None or `str`, optional
    A description of why this Field is deprecated, including removal date.
    If not None, the string is appended to the docstring for this Field.

See also
--------
ChoiceField
ConfigChoiceField
ConfigDictField
ConfigField
ConfigurableField
Field
ListField
RangeField
RegistryField

Examples
--------
This field maps has `str` keys and `int` values:

>>> from lsst.pex.config import Config, DictField
>>> class MyConfig(Config):
...     field = DictField(
...         doc="Example string-to-int mapping field.",
...         keytype=str, itemtype=int,
...         default={})
...
>>> config = MyConfig()
>>> config.field['myKey'] = 42
>>> print(config.field)
{'myKey': 42}

Definition at line 144 of file dictField.py.

Constructor & Destructor Documentation

__init__()

def pex.config.dictField.DictField.__init__	(		self,
			doc,
			keytype,
			itemtype,
			default = None,
			optional = False,
			dictCheck = None,
			itemCheck = None,
			deprecated = None
	)

Reimplemented in pex.config.configDictField.ConfigDictField.

Definition at line 204 of file dictField.py.

    def __init__(self, doc, keytype, itemtype, default=None, optional=False, dictCheck=None, itemCheck=None,
                 deprecated=None):
        source = getStackFrame()
        self._setup(doc=doc, dtype=Dict, default=default, check=None,
                    optional=optional, source=source, deprecated=deprecated)
        if keytype not in self.supportedTypes:
            raise ValueError("'keytype' %s is not a supported type" %
                             _typeStr(keytype))
        elif itemtype is not None and itemtype not in self.supportedTypes:
            raise ValueError("'itemtype' %s is not a supported type" %
                             _typeStr(itemtype))
        if dictCheck is not None and not hasattr(dictCheck, "__call__"):
            raise ValueError("'dictCheck' must be callable")
        if itemCheck is not None and not hasattr(itemCheck, "__call__"):
            raise ValueError("'itemCheck' must be callable")
 
        self.keytype = keytype
        self.itemtype = itemtype
        self.dictCheck = dictCheck
        self.itemCheck = itemCheck
 

Member Function Documentation

__delete__()

def pex.config.config.Field.__delete__ (   self,   instance,   at = None,   label = 'deletion'  )

inherited

Delete an attribute from a `lsst.pex.config.Config` instance.

Parameters
----------
instance : `lsst.pex.config.Config`
    The config instance that contains this field.
at : `list` of `lsst.pex.config.callStack.StackFrame`
    The call stack (created by
    `lsst.pex.config.callStack.getCallStack`).
label : `str`, optional
    Event label for the history.

Notes
-----
This is invoked by the owning `~lsst.pex.config.Config` object and
should not be called directly.

Definition at line 573 of file config.py.

    def __delete__(self, instance, at=None, label='deletion'):
        """Delete an attribute from a `lsst.pex.config.Config` instance.
 
        Parameters
        ----------
        instance : `lsst.pex.config.Config`
            The config instance that contains this field.
        at : `list` of `lsst.pex.config.callStack.StackFrame`
            The call stack (created by
            `lsst.pex.config.callStack.getCallStack`).
        label : `str`, optional
            Event label for the history.
 
        Notes
        -----
        This is invoked by the owning `~lsst.pex.config.Config` object and
        should not be called directly.
        """
        if at is None:
            at = getCallStack()
        self.__set__(instance, None, at=at, label=label)
 

__get__()

def pex.config.config.Field.__get__ (   self,   instance,   owner = None,   at = None,   label = "default"  )

inherited

Define how attribute access should occur on the Config instance
This is invoked by the owning config object and should not be called
directly

When the field attribute is accessed on a Config class object, it
returns the field object itself in order to allow inspection of
Config classes.

When the field attribute is access on a config instance, the actual
value described by the field (and held by the Config instance) is
returned.

Reimplemented in pex.config.configurableField.ConfigurableField.

Definition at line 498 of file config.py.

    def __get__(self, instance, owner=None, at=None, label="default"):
        """Define how attribute access should occur on the Config instance
        This is invoked by the owning config object and should not be called
        directly
 
        When the field attribute is accessed on a Config class object, it
        returns the field object itself in order to allow inspection of
        Config classes.
 
        When the field attribute is access on a config instance, the actual
        value described by the field (and held by the Config instance) is
        returned.
        """
        if instance is None or not isinstance(instance, Config):
            return self
        else:
            return instance._storage[self.name]
 

__set__()

def pex.config.dictField.DictField.__set__	(		self,
			instance,
			value,
			at = None,
			label = "assignment"
	)

Set an attribute on the config instance.

Parameters
----------
instance : `lsst.pex.config.Config`
    The config instance that contains this field.
value : obj
    Value to set on this field.
at : `list` of `lsst.pex.config.callStack.StackFrame`
    The call stack (created by
    `lsst.pex.config.callStack.getCallStack`).
label : `str`, optional
    Event label for the history.

Notes
-----
This method is invoked by the owning `lsst.pex.config.Config` object
and should not be called directly.

Derived `~lsst.pex.config.Field` classes may need to override the
behavior. When overriding ``__set__``, `~lsst.pex.config.Field` authors
should follow the following rules:

- Do not allow modification of frozen configs.
- Validate the new value **before** modifying the field. Except if the
  new value is `None`. `None` is special and no attempt should be made
  to validate it until `lsst.pex.config.Config.validate` is called.
- Do not modify the `~lsst.pex.config.Config` instance to contain
  invalid values.
- If the field is modified, update the history of the
  `lsst.pex.config.field.Field` to reflect the changes.

In order to decrease the need to implement this method in derived
`~lsst.pex.config.Field` types, value validation is performed in the
`lsst.pex.config.Field._validateValue`. If only the validation step
differs in the derived `~lsst.pex.config.Field`, it is simpler to
implement `lsst.pex.config.Field._validateValue` than to reimplement
``__set__``. More complicated behavior, however, may require
reimplementation.

Reimplemented from pex.config.config.Field.

Definition at line 258 of file dictField.py.

    def __set__(self, instance, value, at=None, label="assignment"):
        if instance._frozen:
            msg = "Cannot modify a frozen Config. "\
                  "Attempting to set field to value %s" % value
            raise FieldValidationError(self, instance, msg)
 
        if at is None:
            at = getCallStack()
        if value is not None:
            value = self.DictClass(instance, self, value, at=at, label=label)
        else:
            history = instance._history.setdefault(self.name, [])
            history.append((value, at, label))
 
        instance._storage[self.name] = value
 

freeze()

def pex.config.config.Field.freeze (   self,   instance  )

inherited

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

Parameters
----------
instance : `lsst.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.**

Reimplemented in pex.config.configChoiceField.ConfigChoiceField, pex.config.configurableField.ConfigurableField, pex.config.configDictField.ConfigDictField, and pex.config.configField.ConfigField.

Definition at line 377 of file config.py.

    def freeze(self, instance):
        """Make this field read-only (for internal use only).
 
        Parameters
        ----------
        instance : `lsst.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.**
        """
        pass
 

rename()

def pex.config.config.Field.rename (   self,   instance  )

inherited

Rename the field in a `~lsst.pex.config.Config` (for internal use
only).

Parameters
----------
instance : `lsst.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 `~lsst.pex.config.Field` instances that
hold subconfigs. `~lsst.pex.config.Fields` that hold subconfigs should
rename each subconfig with the full field name as generated by
`lsst.pex.config.config._joinNamePath`.

Reimplemented in pex.config.configChoiceField.ConfigChoiceField, pex.config.configurableField.ConfigurableField, pex.config.configDictField.ConfigDictField, and pex.config.configField.ConfigField.

Definition at line 327 of file config.py.

    def rename(self, instance):
        """Rename the field in a `~lsst.pex.config.Config` (for internal use
        only).
 
        Parameters
        ----------
        instance : `lsst.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 `~lsst.pex.config.Field` instances that
        hold subconfigs. `~lsst.pex.config.Fields` that hold subconfigs should
        rename each subconfig with the full field name as generated by
        `lsst.pex.config.config._joinNamePath`.
        """
        pass
 

save()

def pex.config.config.Field.save (   self,   outfile,   instance  )

inherited

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

Parameters
----------
outfile : file-like object
    A writeable field handle.
instance : `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.

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.

Reimplemented in pex.config.configChoiceField.ConfigChoiceField, pex.config.configurableField.ConfigurableField, pex.config.configDictField.ConfigDictField, and pex.config.configField.ConfigField.

Definition at line 435 of file config.py.

    def save(self, outfile, instance):
        """Save this field to a file (for internal use only).
 
        Parameters
        ----------
        outfile : file-like object
            A writeable field handle.
        instance : `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.
 
        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.
        """
        value = self.__get__(instance)
        fullname = _joinNamePath(instance._name, self.name)
 
        if self.deprecated and value == self.default:
            return
 
        # write full documentation string as comment lines
        # (i.e. first character is #)
        doc = "# " + str(self.doc).replace("\n", "\n# ")
        if isinstance(value, float) and (math.isinf(value) or math.isnan(value)):
            # non-finite numbers need special care
            outfile.write(u"{}\n{}=float('{!r}')\n\n".format(doc, fullname, value))
        else:
            outfile.write(u"{}\n{}={!r}\n\n".format(doc, fullname, value))
 

toDict()

def pex.config.dictField.DictField.toDict	(		self,
			instance
	)

Convert this field's key-value pairs into a regular `dict`.

Parameters
----------
instance : `lsst.pex.config.Config`
    The configuration that contains this field.

Returns
-------
result : `dict` or `None`
    If this field has a value of `None`, then this method returns
    `None`. Otherwise, this method returns the field's value as a
    regular Python `dict`.

Reimplemented from pex.config.config.Field.

Reimplemented in pex.config.configDictField.ConfigDictField.

Definition at line 274 of file dictField.py.

    def toDict(self, instance):
        """Convert this field's key-value pairs into a regular `dict`.
 
        Parameters
        ----------
        instance : `lsst.pex.config.Config`
            The configuration that contains this field.
 
        Returns
        -------
        result : `dict` or `None`
            If this field has a value of `None`, then this method returns
            `None`. Otherwise, this method returns the field's value as a
            regular Python `dict`.
        """
        value = self.__get__(instance)
        return dict(value) if value is not None else None
 

validate()

def pex.config.dictField.DictField.validate	(		self,
			instance
	)

Validate the field's value (for internal use only).

Parameters
----------
instance : `lsst.pex.config.Config`
    The configuration that contains this field.

Returns
-------
isValid : `bool`
    `True` is returned if the field passes validation criteria (see
    *Notes*). Otherwise `False`.

Notes
-----
This method validates values according to the following criteria:

- A non-optional field is not `None`.
- If a value is not `None`, is must pass the `ConfigField.dictCheck`
  user callback functon.

Individual item checks by the `ConfigField.itemCheck` user callback
function are done immediately when the value is set on a key. Those
checks are not repeated by this method.

Reimplemented from pex.config.config.Field.

Reimplemented in pex.config.configDictField.ConfigDictField.

Definition at line 225 of file dictField.py.

    def validate(self, instance):
        """Validate the field's value (for internal use only).
 
        Parameters
        ----------
        instance : `lsst.pex.config.Config`
            The configuration that contains this field.
 
        Returns
        -------
        isValid : `bool`
            `True` is returned if the field passes validation criteria (see
            *Notes*). Otherwise `False`.
 
        Notes
        -----
        This method validates values according to the following criteria:
 
        - A non-optional field is not `None`.
        - If a value is not `None`, is must pass the `ConfigField.dictCheck`
          user callback functon.
 
        Individual item checks by the `ConfigField.itemCheck` user callback
        function are done immediately when the value is set on a key. Those
        checks are not repeated by this method.
        """
        Field.validate(self, instance)
        value = self.__get__(instance)
        if value is not None and self.dictCheck is not None \
                and not self.dictCheck(value):
            msg = "%s is not a valid value" % str(value)
            raise FieldValidationError(self, instance, msg)
 

Member Data Documentation

check

pex.config.config.Field.check

inherited

Definition at line 311 of file config.py.

default

pex.config.config.Field.default

inherited

Definition at line 307 of file config.py.

deprecated

pex.config.config.Field.deprecated

inherited

Definition at line 298 of file config.py.

dictCheck

pex.config.dictField.DictField.dictCheck

Definition at line 221 of file dictField.py.

DictClass

pex.config.dictField.DictField.DictClass = Dict

static

Definition at line 202 of file dictField.py.

doc

pex.config.config.Field.doc

inherited

Definition at line 294 of file config.py.

dtype

pex.config.config.Field.dtype

inherited

Definition at line 287 of file config.py.

itemCheck

pex.config.dictField.DictField.itemCheck

Definition at line 222 of file dictField.py.

itemtype

pex.config.dictField.DictField.itemtype

Definition at line 220 of file dictField.py.

keytype

pex.config.dictField.DictField.keytype

Definition at line 219 of file dictField.py.

optional

pex.config.config.Field.optional

inherited

Definition at line 315 of file config.py.

source

pex.config.config.Field.source

inherited

Definition at line 322 of file config.py.

supportedTypes

pex.config.config.Field.supportedTypes = set((str, bool, float, int, complex))

staticinherited

Definition at line 272 of file config.py.

---

The documentation for this class was generated from the following file:

• /j/snowflake/release/lsstsw/stack/cb4e2dc/Linux64/pex_config/20.0.0+34a42eae2c/python/lsst/pex/config/dictField.py