Dialogue State Tracker¶

The tracker stores and maintains the state of the dialogue with a single user. It is stored in a tracker store, retrieved when incoming messages for the conversation are received and updated after actions have been executed

Here we go:

class rasa_core.trackers.DialogueStateTracker(sender_id, slots, max_event_history=None)[source]¶

Bases: object

Maintains the state of a conversation.

The field max_event_history will only give you these last events, it can be set in the tracker_store

applied_events() → List[rasa_core.events.Event][source]¶

Returns all actions that should be applied - w/o reverted events.

as_dialogue()[source]¶

Return a Dialogue object containing all of the turns.

This can be serialised and later used to recover the state of this tracker exactly.

change_form_to(form_name: str) → None[source]¶

Activate or deactivate a form

clear_followup_action()[source]¶

Clears follow up action when it was executed.

copy()[source]¶

Creates a duplicate of this tracker

current_slot_values()[source]¶

Return the currently set values of the slots

current_state(event_verbosity: rasa_core.trackers.EventVerbosity = <EventVerbosity.NONE: 1>) → Dict[str, Any][source]¶

Return the current tracker state as an object.

events_after_latest_restart()[source]¶

Return a list of events after the most recent restart.

export_stories(e2e=False) → str[source]¶

Dump the tracker as a story in the Rasa Core story format.

Returns the dumped tracker as a string.

export_stories_to_file(export_path: str = 'debug.md') → None[source]¶

Dump the tracker as a story to a file.

classmethod from_dict(sender_id: str, events_as_dict: List[Dict[str, Any]], slots: List[rasa_core.slots.Slot], max_event_history: Optional[int] = None) → rasa_core.trackers.DialogueStateTracker[source]¶

Create a tracker from dump.

The dump should be an array of dumped events. When restoring the tracker, these events will be replayed to recreate the state.

classmethod from_events(sender_id: str, evts: List[rasa_core.events.Event], slots: List[rasa_core.slots.Slot], max_event_history: Optional[int] = None)[source]¶

generate_all_prior_trackers()[source]¶

Returns a generator of the previous trackers of this tracker.

The resulting array is representing the trackers before each action.

get_last_event_for(event_type: Type[rasa_core.events.Event], action_names_to_exclude: List[str] = None, skip: int = 0) → Optional[rasa_core.events.Event][source]¶

Gets the last event of a given type which was actually applied.

Args:

event_type: The type of event you want to find. action_names_to_exclude: Events of type ActionExecuted which

should be excluded from the results. Can be used to skip action_listen events.

skip: Skips n possible results before return an event.

Returns:

event which matched the query or None if no event matched.

get_latest_entity_values(entity_type: str) → Iterator[str][source]¶

Get entity values found for the passed entity name in latest msg.

If you are only interested in the first entity of a given type use next(tracker.get_latest_entity_values(“my_entity_name”), None). If no entity is found None is the default result.

get_latest_input_channel() → Optional[str][source]¶

Get the name of the input_channel of the latest UserUttered event

get_slot(key: str) → Optional[Any][source]¶

Retrieves the value of a slot.

idx_after_latest_restart()[source]¶

Return the idx of the most recent restart in the list of events.

If the conversation has not been restarted, 0 is returned.

init_copy()[source]¶

Creates a new state tracker with the same initial values.

is_paused() → bool[source]¶

State whether the tracker is currently paused.

last_executed_action_has(name: str, skip=0) → bool[source]¶

Returns whether last ActionExecuted event had a specific name.

Args:

name: Name of the event which should be matched. skip: Skips n possible results in between.

Returns:

True if last executed action had name name, otherwise False.

past_states(domain: Domain) → collections.deque[source]¶

Generate the past states of this tracker based on the history.

recreate_from_dialogue(dialogue: rasa_core.conversation.Dialogue) → None[source]¶

Use a serialised Dialogue to update the trackers state.

This uses the state as is persisted in a TrackerStore. If the tracker is blank before calling this method, the final state will be identical to the tracker from which the dialogue was created.

reject_action(action_name: str) → None[source]¶

Notify active form that it was rejected

replay_events()[source]¶

Update the tracker based on a list of events.

set_form_validation(validate: bool) → None[source]¶

Toggle form validation

set_latest_action_name(action_name: str) → None[source]¶

Set latest action name and reset form validation and rejection parameters

travel_back_in_time(target_time: float) → rasa_core.trackers.DialogueStateTracker[source]¶

Creates a new tracker with a state at a specific timestamp.

A new tracker will be created and all events previous to the passed time stamp will be replayed. Events that occur exactly at the target time will be included.

trigger_followup_action(action: str) → None[source]¶

Triggers another action following the execution of the current.

update(event: rasa_core.events.Event) → None[source]¶

Modify the state of the tracker according to an Event.

class rasa_core.trackers.EventVerbosity[source]¶

Bases: enum.Enum

Filter on which events to include in tracker dumps.

AFTER_RESTART = 3¶

ALL = 4¶

APPLIED = 2¶

NONE = 1¶