Source code for chatterbot.logic.best_match
from chatterbot.logic import LogicAdapter
from chatterbot import filters
[docs]
class BestMatch(LogicAdapter):
"""
A logic adapter that returns a response based on known responses to
the closest matches to the input statement.
:param excluded_words:
The excluded_words parameter allows a list of words to be set that will
prevent the logic adapter from returning statements that have text
containing any of those words. This can be useful for preventing your
chat bot from saying swears when it is being demonstrated in front of
an audience.
Defaults to None
:type excluded_words: list
"""
def __init__(self, chatbot, **kwargs):
super().__init__(chatbot, **kwargs)
self.excluded_words = kwargs.get('excluded_words')
def process(self, input_statement, additional_response_selection_parameters=None):
# Get all statements that have a response text similar to the input statement
search_results = self.search_algorithm.search(input_statement)
# Use the input statement as the closest match if no other results are found
input_statement.confidence = 0 # Use 0 confidence when no other results are found
closest_match = input_statement
# Search for the closest match to the input statement
for result in search_results:
closest_match = result
# Stop searching if a match that is close enough is found
if result.confidence >= self.maximum_similarity_threshold:
break
self.chatbot.logger.info('Selecting "{}" as a response to "{}" with a confidence of {}'.format(
closest_match.in_response_to, input_statement.text, closest_match.confidence
))
recent_repeated_responses = filters.get_recent_repeated_responses(
self.chatbot,
input_statement.conversation
)
for index, recent_repeated_response in enumerate(recent_repeated_responses):
self.chatbot.logger.info('{}. Excluding recent repeated response of "{}"'.format(
index, recent_repeated_response
))
response_selection_parameters = {
'search_text': closest_match.search_text,
'persona_not_startswith': 'bot:',
'exclude_text': recent_repeated_responses,
'exclude_text_words': self.excluded_words
}
alternate_response_selection_parameters = {
'search_in_response_to': self.chatbot.tagger.get_text_index_string(
input_statement.text
),
'persona_not_startswith': 'bot:',
'exclude_text': recent_repeated_responses,
'exclude_text_words': self.excluded_words
}
if additional_response_selection_parameters:
response_selection_parameters.update(
additional_response_selection_parameters
)
alternate_response_selection_parameters.update(
additional_response_selection_parameters
)
# Get all statements with text similar to the closest match
response_list = list(self.chatbot.storage.filter(**response_selection_parameters))
if response_list:
response = self.select_response(
input_statement,
response_list,
self.chatbot.storage
)
response.confidence = closest_match.confidence
self.chatbot.logger.info('Selecting "{}" from {} optimal responses.'.format(
response.text,
len(response_list)
))
else:
'''
The case where there was no responses returned for the selected match
but a value exists for the statement the match is in response to.
'''
self.chatbot.logger.info('No responses found. Generating alternate response list.')
alternate_response_list = list(self.chatbot.storage.filter(
**alternate_response_selection_parameters
))
if alternate_response_list:
response = self.select_response(
input_statement,
alternate_response_list,
self.chatbot.storage
)
response.confidence = closest_match.confidence
self.chatbot.logger.info('Selected alternative response "{}" from {} options'.format(
response.text,
len(alternate_response_list)
))
else:
response = self.get_default_response(input_statement)
self.chatbot.logger.info('Using "%s" as a default response.', response.text)
return response
