dicfg.magics.ConfigMagics#

class ConfigMagics(**kwargs: Any)[source]#

Bases: Magics

IPython magic for loading YAML configuration files.

Create a configurable given a config config.

Parameters:

config (Config) – If this is empty, default values are used. If config is a Config instance, it will be used to configure the instance.
parent (Configurable instance, optional) – The parent Configurable instance of this object.

Notes

Subclasses of Configurable must call the __init__() method of Configurable before doing anything else and using super():

class MyConfigurable(Configurable):
    def __init__(self, config=None):
        super(MyConfigurable, self).__init__(config=config)
        # Then any other code you need to finish initialization.

This ensures that instances will be configured properly.

__init__(shell=None, **kwargs)#

Create a configurable given a config config.

Parameters:

config (Config) – If this is empty, default values are used. If config is a Config instance, it will be used to configure the instance.
parent (Configurable instance, optional) – The parent Configurable instance of this object.

Notes

Subclasses of Configurable must call the __init__() method of Configurable before doing anything else and using super():

class MyConfigurable(Configurable):
    def __init__(self, config=None):
        super(MyConfigurable, self).__init__(config=config)
        # Then any other code you need to finish initialization.

This ensures that instances will be configured properly.

Methods

`__init__`([shell])	Create a configurable given a config config.
`add_traits`(**traits)	Dynamically add trait attributes to the HasTraits instance.
`arg_err`(func)	Print docstring if incorrect arguments were passed
`class_config_rst_doc`()	Generate rST documentation for this class' config options.
`class_config_section`([classes])	Get the config section for this class.
`class_get_help`([inst])	Get the help string for this class in ReST format.
`class_get_trait_help`(trait[, inst, helptext])	Get the helptext string for a single trait.
`class_own_trait_events`(name)	Get a dict of all event handlers defined on this class, not a parent.
`class_own_traits`(**metadata)	Get a dict of all the traitlets defined on this class, not a parent.
`class_print_help`([inst])	Get the help string for a single trait and print it.
`class_trait_names`(**metadata)	Get a list of all the names of this class' traits.
`class_traits`(**metadata)	Get a `dict` of all the traits of this class.
`default_option`(fn, optstr)	Make an entry in the options_table for fn, with value optstr
`format_latex`(strng)	Format a string for latex inclusion.
`has_trait`(name)	Returns True if the object has a trait with the specified name.
`hold_trait_notifications`()	Context manager for bundling trait change notifications and cross validation.
`notify_change`(change)	Notify observers of a change event
`observe`(handler[, names, type])	Setup a handler to be called when a trait changes.
`on_trait_change`([handler, name, remove])	DEPRECATED: Setup a handler to be called when a trait changes.
`parse_options`(arg_str, opt_str, long_opts, *kw)	Parse options passed to an argument string.
`register_magics`()	Register the magics with IPython.
`section_names`()	return section names as a list
`set_trait`(name, value)	Forcibly sets trait attribute, including read-only attributes.
`setup_instance`(**kwargs)	This is called before self.__init__ is called.
`trait_defaults`(names, *metadata)	Return a trait's default value or a dictionary of them
`trait_events`([name])	Get a `dict` of all the event handlers of this class.
`trait_has_value`(name)	Returns True if the specified trait has a value.
`trait_metadata`(traitname, key[, default])	Get metadata values for trait by key.
`trait_names`(**metadata)	Get a list of all the names of this class' traits.
`trait_values`(**metadata)	A `dict` of trait names and their values.
`traits`(**metadata)	Get a `dict` of all the traits of this class.
`unobserve`(handler[, names, type])	Remove a trait change handler.
`unobserve_all`([name])	Remove trait change handlers of any type for the specified name.
`update_config`(config)	Update config and load the new values
`yaml`(args, content)

Attributes

`config`	A trait whose value must be an instance of a specified class.
`cross_validation_lock`	A contextmanager for running a block with our cross validation lock set to True.
`magics`
`options_table`
`parent`	A trait whose value must be an instance of a specified class.
`registered`
`shell`

add_traits(**traits: Any) → None#: Dynamically add trait attributes to the HasTraits instance.

arg_err(func)#: Print docstring if incorrect arguments were passed

classmethod class_config_rst_doc() → str#

Generate rST documentation for this class’ config options.

Excludes traits defined on parent classes.

classmethod class_config_section(classes: Sequence[type[HasTraits]] | None = None) → str#

Get the config section for this class.

Parameters:: classes (list, optional) – The list of other classes in the config file. Used to reduce redundant information.

classmethod class_get_help(inst: HasTraits | None = None) → str#

Get the help string for this class in ReST format.

If inst is given, its current trait values will be used in place of class defaults.

classmethod class_get_trait_help(trait: TraitType[Any, Any], inst: HasTraits | None = None, helptext: str | None = None) → str#

Get the helptext string for a single trait.

Parameters:

inst – If given, its current trait values will be used in place of the class default.
helptext – If not given, uses the help attribute of the current trait.

classmethod class_own_trait_events(name: str) → dict[str, EventHandler]#

Get a dict of all event handlers defined on this class, not a parent.

Works like event_handlers, except for excluding traits from parents.

classmethod class_own_traits(**metadata: Any) → dict[str, TraitType[Any, Any]]#

Get a dict of all the traitlets defined on this class, not a parent.

Works like class_traits, except for excluding traits from parents.

classmethod class_print_help(inst: HasTraits | None = None) → None#: Get the help string for a single trait and print it.

classmethod class_trait_names(**metadata: Any) → list[str]#

Get a list of all the names of this class’ traits.

This method is just like the trait_names() method, but is unbound.

classmethod class_traits(**metadata: Any) → dict[str, TraitType[Any, Any]]#

Get a dict of all the traits of this class. The dictionary is keyed on the name and the values are the TraitType objects.

This method is just like the traits() method, but is unbound.

The TraitTypes returned don’t know anything about the values that the various HasTrait’s instances are holding.

The metadata kwargs allow functions to be passed in which filter traits based on metadata values. The functions should take a single value as an argument and return a boolean. If any function returns False, then the trait is not included in the output. If a metadata key doesn’t exist, None will be passed to the function.

property cross_validation_lock: Any#

A contextmanager for running a block with our cross validation lock set to True.

At the end of the block, the lock’s value is restored to its value prior to entering the block.

default_option(fn, optstr)#: Make an entry in the options_table for fn, with value optstr

format_latex(strng)#: Format a string for latex inclusion.

has_trait(name: str) → bool#: Returns True if the object has a trait with the specified name.

hold_trait_notifications() → Any#

Context manager for bundling trait change notifications and cross validation.

Use this when doing multiple trait assignments (init, config), to avoid race conditions in trait notifiers requesting other trait values. All trait notifications will fire after all values have been assigned.

notify_change(change: Bunch) → None#: Notify observers of a change event

observe(handler: Callable[[...], Any], names: Sentinel | str | Iterable[Sentinel | str] = traitlets.All, type: Sentinel | str = 'change') → None#

Setup a handler to be called when a trait changes.

This is used to setup dynamic notifications of trait changes.

Parameters:

handler (callable) – A callable that is called when a trait changes. Its signature should be handler(change), where change is a dictionary. The change dictionary at least holds a ‘type’ key. * type: the type of notification. Other keys may be passed depending on the value of ‘type’. In the case where type is ‘change’, we also have the following keys: * owner : the HasTraits instance * old : the old value of the modified trait attribute * new : the new value of the modified trait attribute * name : the name of the modified trait attribute.
names (list, str, All) – If names is All, the handler will apply to all traits. If a list of str, handler will apply to all names in the list. If a str, the handler will apply just to that name.
type (str, All (default: 'change')) – The type of notification to filter by. If equal to All, then all notifications are passed to the observe handler.

on_trait_change(handler: EventHandler | None = None, name: Sentinel | str | None = None, remove: bool = False) → None#

DEPRECATED: Setup a handler to be called when a trait changes.

This is used to setup dynamic notifications of trait changes.

Static handlers can be created by creating methods on a HasTraits subclass with the naming convention ‘_[traitname]_changed’. Thus, to create static handler for the trait ‘a’, create the method _a_changed(self, name, old, new) (fewer arguments can be used, see below).

If remove is True and handler is not specified, all change handlers for the specified name are uninstalled.

Parameters:

handler (callable, None) – A callable that is called when a trait changes. Its signature can be handler(), handler(name), handler(name, new), handler(name, old, new), or handler(name, old, new, self).
name (list, str, None) – If None, the handler will apply to all traits. If a list of str, handler will apply to all names in the list. If a str, the handler will apply just to that name.
remove (bool) – If False (the default), then install the handler. If True then unintall it.

parse_options(arg_str, opt_str, *long_opts, **kw)#

Parse options passed to an argument string.

The interface is similar to that of getopt.getopt(), but it returns a Struct with the options as keys and the stripped argument string still as a string.

arg_str is quoted as a true sys.argv vector by using shlex.split. This allows us to easily expand variables, glob files, quote arguments, etc.

Parameters:

arg_str (str) – The arguments to parse.
opt_str (str) – The options specification.
mode (str, default 'string') – If given as ‘list’, the argument string is returned as a list (split on whitespace) instead of a string.
list_all (bool, default False) – Put all option values in lists. Normally only options appearing more than once are put in a list.
posix (bool, default True) – Whether to split the input line in POSIX mode or not, as per the conventions outlined in the shlex module from the standard library.

classmethod register_magics()[source]#: Register the magics with IPython.

classmethod section_names() → list[str]#: return section names as a list

set_trait(name: str, value: Any) → None#: Forcibly sets trait attribute, including read-only attributes.

setup_instance(**kwargs: Any) → None#: This is called before self.__init__ is called.

trait_defaults(*names: str, **metadata: Any) → dict[str, Any] | Sentinel#

Return a trait’s default value or a dictionary of them

Notes

Dynamically generated default values may depend on the current state of the object.

classmethod trait_events(name: str | None = None) → dict[str, EventHandler]#

Get a dict of all the event handlers of this class.

Parameters:: name (str (default: None)) – The name of a trait of this class. If name is None then all the event handlers of this class will be returned instead.
Return type:: The event handlers associated with a trait name, or all event handlers.

trait_has_value(name: str) → bool#

Returns True if the specified trait has a value.

This will return false even if getattr would return a dynamically generated default value. These default values will be recognized as existing only after they have been generated.

Example

class MyClass(HasTraits):
    i = Int()


mc = MyClass()
assert not mc.trait_has_value("i")
mc.i  # generates a default value
assert mc.trait_has_value("i")

trait_metadata(traitname: str, key: str, default: Any | None = None) → Any#: Get metadata values for trait by key.

trait_names(**metadata: Any) → list[str]#: Get a list of all the names of this class’ traits.

trait_values(**metadata: Any) → dict[str, Any]#

A dict of trait names and their values.

The metadata kwargs allow functions to be passed in which filter traits based on metadata values. The functions should take a single value as an argument and return a boolean. If any function returns False, then the trait is not included in the output. If a metadata key doesn’t exist, None will be passed to the function.

Return type:: A dict of trait names and their values.

Notes

Trait values are retrieved via getattr, any exceptions raised by traits or the operations they may trigger will result in the absence of a trait value in the result dict.

traits(**metadata: Any) → dict[str, TraitType[Any, Any]]#

Get a dict of all the traits of this class. The dictionary is keyed on the name and the values are the TraitType objects.

The TraitTypes returned don’t know anything about the values that the various HasTrait’s instances are holding.

The metadata kwargs allow functions to be passed in which filter traits based on metadata values. The functions should take a single value as an argument and return a boolean. If any function returns False, then the trait is not included in the output. If a metadata key doesn’t exist, None will be passed to the function.

unobserve(handler: Callable[[...], Any], names: Sentinel | str | Iterable[Sentinel | str] = traitlets.All, type: Sentinel | str = 'change') → None#

Remove a trait change handler.

This is used to unregister handlers to trait change notifications.

Parameters:

handler (callable) – The callable called when a trait attribute changes.
names (list, str, All (default: All)) – The names of the traits for which the specified handler should be uninstalled. If names is All, the specified handler is uninstalled from the list of notifiers corresponding to all changes.
type (str or All (default: 'change')) – The type of notification to filter by. If All, the specified handler is uninstalled from the list of notifiers corresponding to all types.

unobserve_all(name: str | Any = traitlets.All) → None#: Remove trait change handlers of any type for the specified name. If name is not specified, removes all trait notifiers.

update_config(config: Config) → None#: Update config and load the new values

yaml(args, content)[source]#

%yaml config

Load a YAML configuration file into a variable in the IPython namespace.

positional arguments:: config The name to give the loaded configuration object.