Redesign recent_statements to hold the entire current conversation

chatterbot/chatterbot.py

@@ -3,6 +3,7 @@
 from .adapters.input import InputAdapter
 from .adapters.output import OutputAdapter
 from .conversation import Statement
+from .utils.queues import ResponseQueue
 from .utils.module_loading import import_module
 
 
@@ -31,7 +32,8 @@ def __init__(self, name, **kwargs):
             "io_adapter_pairs"
         )
 
-        self.recent_statements = []
+        # The last 10 statement inputs and outputs
+        self.recent_statements = ResponseQueue(maxsize=10)
 
         # The storage adapter must be an instance of StorageAdapter
         self.validate_adapter_class(storage_adapter, StorageAdapter)
@@ -98,8 +100,10 @@ def get_last_statement(self):
         """
         Return the last statement that was received.
         """
-        if self.recent_statements:
-            return self.recent_statements[-1]
+        previous_interaction = self.recent_statements[-1]
+        if previous_interaction:
+            input_statement, output_statement = previous_interaction
+            return output_statement
         return None
 
     def get_response(self, input_item):
@@ -124,7 +128,9 @@ def get_response(self, input_item):
         # Update the database after selecting a response
         self.storage.update(input_statement)
 
-        self.recent_statements.append(response)
+        self.recent_statements.append(
+            (input_statement, response, )
+        )
 
         # Process the response output with the output adapter
         return self.output.process_response(response)

chatterbot/utils/queues.py

@@ -0,0 +1,30 @@
+class ResponseQueue(object):
+    """
+    This is a data structure like a queue.
+    Only a fixed number of items can be added.
+    Once the maximum is reached, when a new item
+    is added the oldest item in the queue will
+    be removed.
+    """
+
+    def __init__(self, maxsize=10):
+        self.maxsize = maxsize
+        self.queue = []
+
+    def append(self, item):
+        if len(self.queue) == self.maxsize:
+            # Remove an element from the top of the list
+            self.queue.pop(0)
+
+        self.queue.append(item)
+
+    def __getitem__(self, index):
+        if self.queue:
+            return self.queue[index]
+        return None
+
+    def __contains__(self, item):
+        """
+        Check if an element is in this queue.
+        """
+        return item in self.queue

tests/test_chatbot.py

@@ -10,17 +10,14 @@ def test_get_last_statement(self):
         returns the last statement that was issued.
         """
         self.chatbot.recent_statements.append(
-            Statement("Test statement 1")
+            (Statement("Test statement 1"), Statement("Test response 1"), )
         )
         self.chatbot.recent_statements.append(
-            Statement("Test statement 2")
-        )
-        self.chatbot.recent_statements.append(
-            Statement("Test statement 3")
+            (Statement("Test statement 2"), Statement("Test response 2"), )
         )
 
         last_statement = self.chatbot.get_last_statement()
-        self.assertEqual(last_statement.text, "Test statement 3")
+        self.assertEqual(last_statement.text, "Test response 2")
 
 
 class ChatterBotResponseTests(ChatBotTestCase):
@@ -58,12 +55,12 @@ def test_statement_saved_empty_database(self):
 
     def test_statement_added_to_recent_response_list(self):
         """
-        A new input statement should be added to the recent response list.
+        An input statement should be added to the recent response list.
         """
         statement_text = "Wow!"
         response = self.chatbot.get_response(statement_text)
 
-        self.assertIn(statement_text, self.chatbot.recent_statements)
+        self.assertIn(statement_text, self.chatbot.recent_statements[0])
         self.assertEqual(response, statement_text)
 
     def test_response_known(self):

tests/test_queues.py

@@ -0,0 +1,25 @@
+from unittest import TestCase
+from chatterbot.utils.queues import ResponseQueue
+
+
+class ResponseQueueTests(TestCase):
+
+    def setUp(self):
+        self.queue = ResponseQueue(maxsize=2)
+
+    def test_append(self):
+        self.queue.append(0)
+        self.assertIn(0, self.queue)
+
+    def test_contains(self):
+        self.queue.queue.append(0)
+        self.assertIn(0, self.queue)
+
+    def test_maxsize(self):
+        self.queue.append(0)
+        self.queue.append(1)
+        self.queue.append(2)
+
+        self.assertNotIn(0, self.queue)
+        self.assertIn(1, self.queue)
+        self.assertIn(2, self.queue)