lsst.pex.config.listField.ListField Class Reference

Inheritance diagram for lsst.pex.config.listField.ListField:

Public Member Functions
def	__init__ (self, doc, dtype, default=None, optional=False, listCheck=None, itemCheck=None, length=None, minLength=None, maxLength=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
	listCheck
	itemCheck
	itemtype
	length
	minLength
	maxLength
	dtype
	doc
	default
	check
	optional
	source

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

Detailed Description

A configuration field (`~lsst.pex.config.Field` subclass) that contains
a list of values of a specific type.

Parameters
----------
doc : `str`
    A description of the field.
dtype : class
    The data type of items in the list.
default : sequence, optional
    The default items for the field.
optional : `bool`, optional
    Set whether the field is *optional*. When `False`,
    `lsst.pex.config.Config.validate` will fail if the field's value is
    `None`.
listCheck : callable, optional
    A callable that validates the list as a whole.
itemCheck : callable, optional
    A callable that validates individual items in the list.
length : `int`, optional
    If set, this field must contain exactly ``length`` number of items.
minLength : `int`, optional
    If set, this field must contain *at least* ``minLength`` number of
    items.
maxLength : `int`, optional
    If set, this field must contain *no more than* ``maxLength`` number of
    items.

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

Definition at line 211 of file listField.py.

Constructor & Destructor Documentation

__init__()

def lsst.pex.config.listField.ListField.__init__	(		self,
			doc,
			dtype,
			default = None,
			optional = False,
			listCheck = None,
			itemCheck = None,
			length = None,
			minLength = None,
			maxLength = None
	)

Definition at line 254 of file listField.py.

                 length=None, minLength=None, maxLength=None):
        if dtype not in Field.supportedTypes:
            raise ValueError("Unsupported dtype %s" % _typeStr(dtype))
        if length is not None:
            if length <= 0:
                raise ValueError("'length' (%d) must be positive" % length)
            minLength = None
            maxLength = None
        else:
            if maxLength is not None and maxLength <= 0:
                raise ValueError("'maxLength' (%d) must be positive" % maxLength)
            if minLength is not None and maxLength is not None \
                    and minLength > maxLength:
                raise ValueError("'maxLength' (%d) must be at least"
                                 " as large as 'minLength' (%d)" % (maxLength, minLength))

        if listCheck is not None and not hasattr(listCheck, "__call__"):
            raise ValueError("'listCheck' must be callable")
        if itemCheck is not None and not hasattr(itemCheck, "__call__"):
            raise ValueError("'itemCheck' must be callable")

        source = getStackFrame()
        self._setup(doc=doc, dtype=List, default=default, check=None, optional=optional, source=source)

        self.listCheck = listCheck
        """Callable used to check the list as a whole.
        """

        self.itemCheck = itemCheck
        """Callable used to validate individual items as they are inserted
        into the list.
        """

        self.itemtype = dtype
        """Data type of list items.
        """

        self.length = length
        """Number of items that must be present in the list (or `None` to
        disable checking the list's length).
        """

        self.minLength = minLength
        """Minimum number of items that must be present in the list (or `None`
        to disable checking the list's minimum length).
        """

        self.maxLength = maxLength
        """Maximum number of items that must be present in the list (or `None`
        to disable checking the list's maximum length).
        """

Member Function Documentation

__delete__()

def lsst.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 551 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 lsst.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.

Definition at line 476 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 lsst.pex.config.listField.ListField.__set__	(		self,
			instance,
			value,
			at = None,
			label = "assignment"
	)

Definition at line 346 of file listField.py.

    def __set__(self, instance, value, at=None, label="assignment"):
        if instance._frozen:
            raise FieldValidationError(self, instance, "Cannot modify a frozen Config")

        if at is None:
            at = getCallStack()

        if value is not None:
            value = List(instance, self, value, at, label)
        else:
            history = instance._history.setdefault(self.name, [])
            history.append((value, at, label))

        instance._storage[self.name] = value

freeze()

def lsst.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.**

Definition at line 359 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 lsst.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`.

Definition at line 309 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 lsst.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.

Definition at line 417 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)

        # 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 lsst.pex.config.listField.ListField.toDict	(		self,
			instance
	)

Convert the value of this field to a plain `list`.

`lsst.pex.config.Config.toDict` is the primary user of this method.

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

Returns
-------
`list`
    Plain `list` of items, or `None` if the field is not set.

Definition at line 361 of file listField.py.

    def toDict(self, instance):
        """Convert the value of this field to a plain `list`.

        `lsst.pex.config.Config.toDict` is the primary user of this method.

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

        Returns
        -------
        `list`
            Plain `list` of items, or `None` if the field is not set.
        """
        value = self.__get__(instance)
        return list(value) if value is not None else None

validate()

def lsst.pex.config.listField.ListField.validate	(		self,
			instance
	)

Validate the field.

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

Raises
------
lsst.pex.config.FieldValidationError
    Raised if:

    - The field is not optional, but the value is `None`.
    - The list itself does not meet the requirements of the `length`,
      `minLength`, or `maxLength` attributes.
    - The `listCheck` callable returns `False`.

Notes
-----
Individual item checks (`itemCheck`) are applied when each item is
set and are not re-checked by this method.

Definition at line 306 of file listField.py.

    def validate(self, instance):
        """Validate the field.

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

        Raises
        ------
        lsst.pex.config.FieldValidationError
            Raised if:

            - The field is not optional, but the value is `None`.
            - The list itself does not meet the requirements of the `length`,
              `minLength`, or `maxLength` attributes.
            - The `listCheck` callable returns `False`.

        Notes
        -----
        Individual item checks (`itemCheck`) are applied when each item is
        set and are not re-checked by this method.
        """
        Field.validate(self, instance)
        value = self.__get__(instance)
        if value is not None:
            lenValue = len(value)
            if self.length is not None and not lenValue == self.length:
                msg = "Required list length=%d, got length=%d" % (self.length, lenValue)
                raise FieldValidationError(self, instance, msg)
            elif self.minLength is not None and lenValue < self.minLength:
                msg = "Minimum allowed list length=%d, got length=%d" % (self.minLength, lenValue)
                raise FieldValidationError(self, instance, msg)
            elif self.maxLength is not None and lenValue > self.maxLength:
                msg = "Maximum allowed list length=%d, got length=%d" % (self.maxLength, lenValue)
                raise FieldValidationError(self, instance, msg)
            elif self.listCheck is not None and not self.listCheck(value):
                msg = "%s is not a valid value" % str(value)
                raise FieldValidationError(self, instance, msg)

Member Data Documentation

check

lsst.pex.config.config.Field.check

inherited

Definition at line 293 of file config.py.

default

lsst.pex.config.config.Field.default

inherited

Definition at line 289 of file config.py.

doc

lsst.pex.config.config.Field.doc

inherited

Definition at line 280 of file config.py.

dtype

lsst.pex.config.config.Field.dtype

inherited

Definition at line 276 of file config.py.

itemCheck

lsst.pex.config.listField.ListField.itemCheck

Definition at line 282 of file listField.py.

itemtype

lsst.pex.config.listField.ListField.itemtype

Definition at line 287 of file listField.py.

length

lsst.pex.config.listField.ListField.length

Definition at line 291 of file listField.py.

listCheck

lsst.pex.config.listField.ListField.listCheck

Definition at line 278 of file listField.py.

maxLength

lsst.pex.config.listField.ListField.maxLength

Definition at line 301 of file listField.py.

minLength

lsst.pex.config.listField.ListField.minLength

Definition at line 296 of file listField.py.

optional

lsst.pex.config.config.Field.optional

inherited

Definition at line 297 of file config.py.

source

lsst.pex.config.config.Field.source

inherited

Definition at line 304 of file config.py.

supportedTypes

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

staticinherited

Definition at line 262 of file config.py.

---

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

• /j/snowflake/release/lsstsw/stack/Linux64/pex_config/17.0.1-2-g54f2ebc+9/python/lsst/pex/config/listField.py