Combine logic-adapter features into base class.

The functionality of the no-knowledge adapter and the default
response adapter can be recreated by adding a default response
function to the parent class for logic-adapters.

chatterbot/chatterbot.py

@@ -24,11 +24,6 @@ def __init__(self, name, **kwargs):
 
         storage_adapter = kwargs.get('storage_adapter', 'chatterbot.storage.SQLStorageAdapter')
 
-        # These are logic adapters that are required for normal operation
-        system_logic_adapters = kwargs.get('system_logic_adapters', (
-            'chatterbot.logic.NoKnowledgeAdapter',
-        ))
-
         logic_adapters = kwargs.get('logic_adapters', [
             'chatterbot.logic.BestMatch'
         ])
@@ -45,19 +40,10 @@ def __init__(self, name, **kwargs):
         # Logic adapters used by the chat bot
         self.logic_adapters = []
 
-        # Required logic adapters that must always be present
-        self.system_logic_adapters = []
-
         self.storage = utils.initialize_class(storage_adapter, **kwargs)
         self.input = utils.initialize_class(input_adapter, self, **kwargs)
         self.output = utils.initialize_class(output_adapter, self, **kwargs)
 
-        # Add required system logic adapter
-        for system_logic_adapter in system_logic_adapters:
-            utils.validate_adapter_class(system_logic_adapter, LogicAdapter)
-            logic_adapter = utils.initialize_class(system_logic_adapter, self, **kwargs)
-            self.system_logic_adapters.append(logic_adapter)
-
         for adapter in logic_adapters:
             utils.validate_adapter_class(adapter, LogicAdapter)
             logic_adapter = utils.initialize_class(adapter, self, **kwargs)
@@ -165,7 +151,7 @@ def generate_response(self, input_statement):
         result = None
         max_confidence = -1
 
-        for adapter in self.get_logic_adapters():
+        for adapter in self.logic_adapters:
             if adapter.can_process(input_statement):
 
                 output = adapter.process(input_statement)
@@ -267,11 +253,5 @@ def get_latest_response(self, conversation):
 
         return None
 
-    def get_logic_adapters(self):
-        """
-        Return a list of all logic adapters being used, including system logic adapters.
-        """
-        return self.logic_adapters + self.system_logic_adapters
-
     class ChatBotException(Exception):
         pass

chatterbot/logic/__init__.py

@@ -1,18 +1,14 @@
 from chatterbot.logic.logic_adapter import LogicAdapter
 from chatterbot.logic.best_match import BestMatch
-from chatterbot.logic.low_confidence import LowConfidenceAdapter
 from chatterbot.logic.mathematical_evaluation import MathematicalEvaluation
-from chatterbot.logic.no_knowledge_adapter import NoKnowledgeAdapter
 from chatterbot.logic.specific_response import SpecificResponseAdapter
 from chatterbot.logic.time_adapter import TimeLogicAdapter
 from chatterbot.logic.unit_conversion import UnitConversion
 
 __all__ = (
     'LogicAdapter',
     'BestMatch',
-    'LowConfidenceAdapter',
     'MathematicalEvaluation',
-    'NoKnowledgeAdapter',
     'SpecificResponseAdapter',
     'TimeLogicAdapter',
     'UnitConversion',

chatterbot/logic/best_match.py

@@ -1,5 +1,4 @@
 from chatterbot.logic import LogicAdapter
-from chatterbot.storage import StorageAdapter
 from chatterbot import filters
 
 
@@ -23,13 +22,6 @@ def __init__(self, chatbot, **kwargs):
 
         self.excluded_words = kwargs.get('excluded_words')
 
-    def can_process(self, statement):
-        """
-        Check that the chatbot's storage adapter is available to the logic
-        adapter and there is at least one statement in the database.
-        """
-        return self.chatbot.storage.count()
-
     def process(self, input_statement):
         search_results = self.search_algorithm.search(input_statement)
 
@@ -111,17 +103,6 @@ def process(self, input_statement):
             response.confidence = closest_match.confidence
             self.chatbot.logger.info('Alternate response selected. Using "{}"'.format(response.text))
         else:
-            try:
-                response = self.chatbot.storage.get_random()
-            except StorageAdapter.EmptyDatabaseException:
-                response = input_statement
-            self.chatbot.logger.info(
-                'No response to "{}" found. Selecting a random response.'.format(
-                    closest_match.text
-                )
-            )
-
-            # Set confidence to zero because a random response is selected
-            response.confidence = 0
+            response = self.get_default_response(input_statement)
 
         return response

chatterbot/logic/logic_adapter.py

@@ -1,5 +1,7 @@
 from chatterbot.adapters import Adapter
+from chatterbot.storage import StorageAdapter
 from chatterbot.search import IndexedTextSearch
+from chatterbot.conversation import Statement
 
 
 class LogicAdapter(Adapter):
@@ -18,8 +20,15 @@ class LogicAdapter(Adapter):
         is found or the search set is exhausted.
         Defaults to 0.95
 
-    :param response_selection_method: The a response selection method.
-        Defaults to ``get_first_response``.
+    :param response_selection_method:
+          The a response selection method.
+          Defaults to ``get_first_response``
+    :type response_selection_method: collections.abc.Callable
+
+    :param default_response:
+          The default response returned by this logic adaper
+          if there is no other possible response to return.
+    :type default_response: str or list or tuple
     """
 
     def __init__(self, chatbot, **kwargs):
@@ -45,6 +54,18 @@ def __init__(self, chatbot, **kwargs):
             get_first_response
         )
 
+        default_responses = kwargs.get('default_response', [])
+
+        # Convert a single string into a list
+        if isinstance(default_responses, str):
+            default_responses = [
+                default_responses
+            ]
+
+        self.default_responses = [
+            Statement(text=default) for default in default_responses
+        ]
+
     def can_process(self, statement):
         """
         A preliminary check that is called to determine if a
@@ -75,6 +96,30 @@ def process(self, statement):
         """
         raise self.AdapterMethodNotImplementedError()
 
+    def get_default_response(self, input_statement):
+        """
+        This method is called when a logic adapter is unable to generate any
+        other meaningful response.
+        """
+        from random import choice
+
+        if self.default_responses:
+            response = choice(self.default_responses)
+        else:
+            try:
+                response = self.chatbot.storage.get_random()
+            except StorageAdapter.EmptyDatabaseException:
+                response = input_statement
+
+        self.chatbot.logger.info(
+            'No known response to the input was found. Selecting a random response.'
+        )
+
+        # Set confidence to zero because a random response is selected
+        response.confidence = 0
+
+        return response
+
     @property
     def class_name(self):
         """

chatterbot/storage/django_storage.py

@@ -193,7 +193,13 @@ def get_random(self):
         Returns a random statement from the database
         """
         Statement = self.get_model('statement')
-        return Statement.objects.order_by('?').first()
+
+        statement = Statement.objects.order_by('?').first()
+
+        if statement is None:
+            raise self.EmptyDatabaseException()
+
+        return statement
 
     def remove(self, statement_text):
         """

docs/logic/index.rst

@@ -113,21 +113,6 @@ This adapter is able to handle any combination of word and numeric operators.
    Bot: (4 + 4) = 8
 
 
-Low Confidence Response Adapter
-===============================
-
-This adapter returns a specified default response if a response can not be
-determined with a high amount of confidence.
-
-.. autofunction:: chatterbot.logic.LowConfidenceAdapter
-
-Low confidence response example
--------------------------------
-
-.. literalinclude:: ../../examples/default_response_example.py
-   :language: python
-
-
 Specific Response Adapter
 =========================
 
@@ -141,3 +126,9 @@ Specific response example
 
 .. literalinclude:: ../../examples/specific_response_example.py
    :language: python
+
+Low confidence response example
+-------------------------------
+
+.. literalinclude:: ../../examples/default_response_example.py
+   :language: python

examples/default_response_example.py

@@ -8,11 +8,7 @@
     storage_adapter='chatterbot.storage.SQLStorageAdapter',
     logic_adapters=[
         {
-            'import_path': 'chatterbot.logic.BestMatch'
-        },
-        {
-            'import_path': 'chatterbot.logic.LowConfidenceAdapter',
-            'threshold': 0.65,
+            'import_path': 'chatterbot.logic.BestMatch',
             'default_response': 'I am sorry, but I do not understand.'
         }
     ]

examples/django_app/tests/test_api.py

@@ -6,7 +6,7 @@
 class ApiTestCase(TestCase):
 
     def setUp(self):
-        super(ApiTestCase, self).setUp()
+        super().setUp()
         self.api_url = reverse('chatterbot')
 
     def test_invalid_text(self):

examples/django_app/tests/test_example.py

@@ -6,7 +6,7 @@
 class ViewTestCase(TestCase):
 
     def setUp(self):
-        super(ViewTestCase, self).setUp()
+        super().setUp()
         self.url = reverse('main')
 
     def test_get_main_page(self):
@@ -24,7 +24,7 @@ class ApiTestCase(TestCase):
     """
 
     def setUp(self):
-        super(ApiTestCase, self).setUp()
+        super().setUp()
         self.api_url = reverse('chatterbot')
 
     def test_post(self):
@@ -73,7 +73,7 @@ class ApiIntegrationTestCase(TestCase):
     """
 
     def setUp(self):
-        super(ApiIntegrationTestCase, self).setUp()
+        super().setUp()
         self.api_url = reverse('chatterbot')
 
     def test_get(self):