Warning: This document is for an old version of Rasa Core.

Source code for rasa_core.slots

import logging

from rasa_core import utils

logger = logging.getLogger(__name__)

[docs]class Slot(object): type_name = None def __init__(self, name, initial_value=None, value_reset_delay=None, auto_fill=True): self.name = name self.value = initial_value self.initial_value = initial_value self._value_reset_delay = value_reset_delay self.auto_fill = auto_fill
[docs] def feature_dimensionality(self): """How many features this single slot creates. The dimensionality of the array returned by `as_feature` needs to correspond to this value.""" return 1
def has_features(self): """Indicate if the slot creates any features.""" return self.feature_dimensionality() != 0 def value_reset_delay(self): """After how many turns the slot should be reset to the initial_value. If the delay is set to `None`, the slot will keep its value forever.""" # TODO: FUTURE this needs to be implemented - slots are not reset yet return self._value_reset_delay
[docs] def as_feature(self): raise NotImplementedError("Each slot type needs to specify how its " "value can be converted to a feature. Slot " "'{}' is a generic slot that can not be used " "for predictions. Make sure you add this " "slot to your domain definition, specifying " "the type of the slot. If you implemented " "a custom slot type class, make sure to " "implement `.as_feature()`." "".format(self.name))
def reset(self): self.value = self.initial_value def __str__(self): return "{}({}: {})".format(self.__class__.__name__, self.name, self.value) def __repr__(self): return "<{}({}: {})>".format(self.__class__.__name__, self.name, self.value) @staticmethod def resolve_by_type(type_name): """Returns a slots class by its type name.""" for cls in utils.all_subclasses(Slot): if cls.type_name == type_name: return cls try: return utils.class_from_module_path(type_name) except(ImportError, AttributeError): raise ValueError( "Failed to find slot type, '{}' is neither a known type nor " "user-defined. If you are creating your own slot type, make " "sure its module path is correct.".format(type_name)) def persistence_info(self): return {"type": utils.module_path_from_instance(self), "initial_value": self.initial_value, "auto_fill": self.auto_fill}
class FloatSlot(Slot): type_name = "float" def __init__(self, name, initial_value=None, value_reset_delay=None, auto_fill=True, max_value=1.0, min_value=0.0): super(FloatSlot, self).__init__(name, initial_value, value_reset_delay, auto_fill) self.max_value = max_value self.min_value = min_value if min_value >= max_value: raise ValueError( "Float slot ('{}') created with an invalid range " "using min ({}) and max ({}) values. Make sure " "min is smaller than max." "".format(self.name, self.min_value, self.max_value)) if (initial_value is not None and not (min_value <= initial_value <= max_value)): logger.warning("Float slot ('{}') created with an initial value {}" "outside of configured min ({}) and max ({}) values." "".format(self.name, self.value, self.min_value, self.max_value)) def as_feature(self): try: capped_value = max(self.min_value, min(self.max_value, float(self.value))) if abs(self.max_value - self.min_value) > 0: covered_range = abs(self.max_value - self.min_value) else: covered_range = 1 return [(capped_value - self.min_value) / covered_range] except (TypeError, ValueError): return [0.0] def persistence_info(self): d = super(FloatSlot, self).persistence_info() d["max_value"] = self.max_value d["min_value"] = self.min_value return d class BooleanSlot(Slot): type_name = "bool" def as_feature(self): try: if self.value is not None: return [1.0, float(float(self.value) != 0.0)] else: return [0.0, 0.0] except (TypeError, ValueError): # we couldn't convert the value to float - using default value return [0.0, 0.0] def feature_dimensionality(self): return len(self.as_feature()) class TextSlot(Slot): type_name = "text" def as_feature(self): return [1.0 if self.value is not None else 0.0] class ListSlot(Slot): type_name = "list" def as_feature(self): try: if self.value is not None and len(self.value) > 0: return [1.0] else: return [0.0] except (TypeError, ValueError): # we couldn't convert the value to a list - using default value return [0.0] class UnfeaturizedSlot(Slot): type_name = "unfeaturized" def as_feature(self): return [] def feature_dimensionality(self): return 0 class CategoricalSlot(Slot): type_name = "categorical" def __init__(self, name, values=None, initial_value=None, value_reset_delay=None, auto_fill=True): super(CategoricalSlot, self).__init__(name, initial_value, value_reset_delay, auto_fill) self.values = [str(v).lower() for v in values] if values else [] def persistence_info(self): d = super(CategoricalSlot, self).persistence_info() d["values"] = self.values return d def as_feature(self): r = [0.0] * self.feature_dimensionality() try: for i, v in enumerate(self.values): if v == str(self.value).lower(): r[i] = 1.0 break else: if self.value is not None: logger.warning( "Categorical slot '{}' is set to a value ('{}') " "that is not specified in the domain. " "Value will be ignored and the slot will " "behave as if no value is set. " "Make sure to add all values a categorical " "slot should store to the domain." "".format(self.name, self.value)) except (TypeError, ValueError): logger.exception("Failed to featurize categorical slot.") return r return r def feature_dimensionality(self): return len(self.values) class DataSlot(Slot): def __init__(self, name, initial_value=None, value_reset_delay=1, auto_fill=True): super(DataSlot, self).__init__(name, initial_value, value_reset_delay, auto_fill) def as_feature(self): raise NotImplementedError("Each slot type needs to specify how its " "value can be converted to a feature.")