## Policy Objects

### class Policy()
Common parent class for all dialogue policies.

#### supported_data
@staticmethod

```python
supported_data() -> "SupportedData"
```
The type of data supported by this policy.  
By default, this is only ML-based training data. If policies support rule data, or both ML-based data and rule data, they need to override this method.  
**Returns**:
The data type supported by this policy (ML-based training data).

#### __init__
```python
__init__(featurizer: Optional[TrackerFeaturizer] = None, priority: int = DEFAULT_POLICY_PRIORITY, should_finetune: bool = False, **kwargs: Any) -> None
```
Constructs a new Policy object.

#### featurizer
@property
```python
featurizer() -> TrackerFeaturizer
```
Returns the policy's featurizer.

#### set_shared_policy_states
```python
set_shared_policy_states(**kwargs: Any) -> None
```
Sets policy's shared states for correct featurization.

#### train
```python
train(training_trackers: List[TrackerWithCachedStates], domain: Domain, interpreter: NaturalLanguageInterpreter, **kwargs: Any) -> None
```
Trains the policy on given training trackers.

**Arguments**:
- `training_trackers` - the list of the `rasa.core.trackers.DialogueStateTracker`
- `domain` - the `rasa.shared.core.domain.Domain`
- `interpreter` - Interpreter which can be used by the policies for featurization.
- `**kwargs` - Additional keyword arguments.

#### predict_action_probabilities
```python
predict_action_probabilities(tracker: DialogueStateTracker, domain: Domain, interpreter: NaturalLanguageInterpreter, **kwargs: Any) -> "PolicyPrediction"
```
Predicts the next action the bot should take after seeing the tracker.

**Arguments**:
- `tracker` - the `rasa.core.trackers.DialogueStateTracker`
- `domain` - the `rasa.shared.core.domain.Domain`
- `interpreter` - Interpreter which may be used by the policies to create additional features.

**Returns**:
The policy's prediction (e.g. the probabilities for the actions).

#### persist
```python
persist(path: Union[Text, Path]) -> None
```
Persists the policy to storage.

**Arguments**:
- `path` - Path to persist policy to.

#### load
```python
@classmethod
load(cls, path: Union[Text, Path], **kwargs: Any) -> "Policy"
```
Loads a policy from path.

**Arguments**:
- `path` - Path to load policy from.

**Returns**:
An instance of `Policy`.

#### format_tracker_states
```python
@staticmethod
format_tracker_states(states: List[Dict]) -> Text
```
Format tracker states to human readable format on debug log.

**Arguments**:
- `states` - list of tracker states dicts

**Returns**:
the string of the states with user intents and actions.