Warning: This document is for an old version of Rasa. The latest version is 1.3.3.

Tracker

class rasa.core.trackers.DialogueStateTracker(sender_id, slots, max_event_history=None)

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()

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

Return type:List[Event]
as_dialogue()

Return a Dialogue object containing all of the turns.

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

Return type:Dialogue
change_form_to(form_name)

Activate or deactivate a form

Return type:None
clear_followup_action()

Clears follow up action when it was executed.

Return type:None
copy()

Creates a duplicate of this tracker

current_slot_values()

Return the currently set values of the slots

Return type:Dict[str, Any]
current_state(event_verbosity=<EventVerbosity.NONE: 1>)

Return the current tracker state as an object.

Return type:Dict[str, Any]
events_after_latest_restart()

Return a list of events after the most recent restart.

Return type:List[Event]
export_stories(e2e=False)

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

Returns the dumped tracker as a string.

Return type:str
export_stories_to_file(export_path='debug.md')

Dump the tracker as a story to a file.

Return type:None
classmethod from_dict(sender_id, events_as_dict, slots=None, max_event_history=None)

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.

Return type:DialogueStateTracker
generate_all_prior_trackers()

Returns a generator of the previous trackers of this tracker.

The resulting array is representing the trackers before each action.

Return type:Generator[DialogueStateTracker, None, None]
get_last_event_for(event_type, action_names_to_exclude=None, skip=0)

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

Parameters:
  • 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.

Return type:

Optional[Event]

get_latest_entity_values(entity_type)

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.

Return type:Iterator[str]
get_latest_input_channel()

Get the name of the input_channel of the latest UserUttered event

Return type:Optional[str]
get_slot(key)

Retrieves the value of a slot.

Return type:Optional[Any]
idx_after_latest_restart()

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

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

Return type:int
init_copy()

Creates a new state tracker with the same initial values.

Return type:DialogueStateTracker
is_paused()

State whether the tracker is currently paused.

Return type:bool
last_executed_action_has(name, skip=0)

Returns whether last ActionExecuted event had a specific name.

Parameters:
  • 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.

Return type:

bool

past_states(domain)

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

Return type:deque
recreate_from_dialogue(dialogue)

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.

Return type:None
reject_action(action_name)

Notify active form that it was rejected

Return type:None
replay_events()

Update the tracker based on a list of events.

Return type:None
set_form_validation(validate)

Toggle form validation

Return type:None
set_latest_action_name(action_name)

Set latest action name and reset form validation and rejection parameters

Return type:None
travel_back_in_time(target_time)

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.

Return type:DialogueStateTracker
trigger_followup_action(action)

Triggers another action following the execution of the current.

Return type:None
update(event, domain=None)

Modify the state of the tracker according to an Event.

Return type:None