lsst.pex.config  16.0-13-g118c103+2
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.pex.config.choiceField.ChoiceField Class Reference
Inheritance diagram for lsst.pex.config.choiceField.ChoiceField:
lsst.pex.config.config.Field

Public Member Functions

def __init__ (self, doc, dtype, allowed, default=None, optional=True)
 
def rename (self, instance)
 
def validate (self, instance)
 
def freeze (self, instance)
 
def save (self, outfile, instance)
 
def toDict (self, instance)
 
def __get__ (self, instance, owner=None, at=None, label="default")
 
def __set__ (self, instance, value, at=None, label='assignment')
 
def __delete__ (self, instance, at=None, label='deletion')
 

Public Attributes

 allowed
 
 source
 
 dtype
 
 doc
 
 default
 
 check
 
 optional
 

Static Public Attributes

 supportedTypes = set((str, bool, float, int, complex))
 

Detailed Description

A configuration field (`~lsst.pex.config.Field` subclass) that allows a
user to select from a predefined set of values.

Use ``ChoiceField`` when a configuration can only take one of a predefined
set of values. Each choice must be of the same type.

Parameters
----------
doc : `str`
    Documentation string that describes the configuration field.
dtype : class
    The type of the field's choices. For example, `str` or `int`.
allowed : `dict`
    The allowed values. Keys are the allowed choices (of ``dtype``-type).
    Values are descriptions (`str`-type) of each choice.
default : ``dtype``-type, optional
    The default value, which is of type ``dtype`` and one of the allowed
    choices.
optional : `bool`, optional
    If `True`, this configuration field is *optional*. Default is `True`.

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

Definition at line 28 of file choiceField.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.pex.config.choiceField.ChoiceField.__init__ (   self,
  doc,
  dtype,
  allowed,
  default = None,
  optional = True 
)

Definition at line 62 of file choiceField.py.

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 528 of file config.py.

◆ __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 453 of file config.py.

◆ __set__()

def lsst.pex.config.config.Field.__set__ (   self,
  instance,
  value,
  at = None,
  label = 'assignment' 
)
inherited
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.

Definition at line 471 of file config.py.

◆ 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 350 of file config.py.

◆ 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 300 of file config.py.

◆ 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 394 of file config.py.

◆ toDict()

def lsst.pex.config.config.Field.toDict (   self,
  instance 
)
inherited
Convert the field value so that it can be set as the value of an
item in a `dict` (for internal use only).

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

Returns
-------
value : object
    The field's value. See *Notes*.

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

Simple values are passed through. Complex data structures must be
manipulated. For example, a `~lsst.pex.config.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.

Definition at line 426 of file config.py.

◆ validate()

def lsst.pex.config.config.Field.validate (   self,
  instance 
)
inherited
Validate the field (for internal use only).

Parameters
----------
instance : `lsst.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 `~lsst.pex.config.Field` subclasses should call
`lsst.pex.config.field.Field.validate` if they re-implement
`~lsst.pex.config.field.Field.validate`.

Definition at line 321 of file config.py.

Member Data Documentation

◆ allowed

lsst.pex.config.choiceField.ChoiceField.allowed

Definition at line 63 of file choiceField.py.

◆ check

lsst.pex.config.config.Field.check
inherited

Definition at line 284 of file config.py.

◆ default

lsst.pex.config.config.Field.default
inherited

Definition at line 280 of file config.py.

◆ doc

lsst.pex.config.config.Field.doc
inherited

Definition at line 271 of file config.py.

◆ dtype

lsst.pex.config.config.Field.dtype
inherited

Definition at line 267 of file config.py.

◆ optional

lsst.pex.config.config.Field.optional
inherited

Definition at line 288 of file config.py.

◆ source

lsst.pex.config.choiceField.ChoiceField.source

Definition at line 80 of file choiceField.py.

◆ supportedTypes

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

Definition at line 253 of file config.py.


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