You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
129 lines
3.9 KiB
Python
129 lines
3.9 KiB
Python
# Natural Language Toolkit: Chatbot Utilities
|
|
#
|
|
# Copyright (C) 2001-2019 NLTK Project
|
|
# Authors: Steven Bird <stevenbird1@gmail.com>
|
|
# URL: <http://nltk.org/>
|
|
# For license information, see LICENSE.TXT
|
|
|
|
# Based on an Eliza implementation by Joe Strout <joe@strout.net>,
|
|
# Jeff Epler <jepler@inetnebr.com> and Jez Higgins <jez@jezuk.co.uk>.
|
|
from __future__ import print_function
|
|
|
|
import re
|
|
import random
|
|
|
|
from six.moves import input
|
|
|
|
|
|
reflections = {
|
|
"i am": "you are",
|
|
"i was": "you were",
|
|
"i": "you",
|
|
"i'm": "you are",
|
|
"i'd": "you would",
|
|
"i've": "you have",
|
|
"i'll": "you will",
|
|
"my": "your",
|
|
"you are": "I am",
|
|
"you were": "I was",
|
|
"you've": "I have",
|
|
"you'll": "I will",
|
|
"your": "my",
|
|
"yours": "mine",
|
|
"you": "me",
|
|
"me": "you",
|
|
}
|
|
|
|
|
|
class Chat(object):
|
|
def __init__(self, pairs, reflections={}):
|
|
"""
|
|
Initialize the chatbot. Pairs is a list of patterns and responses. Each
|
|
pattern is a regular expression matching the user's statement or question,
|
|
e.g. r'I like (.*)'. For each such pattern a list of possible responses
|
|
is given, e.g. ['Why do you like %1', 'Did you ever dislike %1']. Material
|
|
which is matched by parenthesized sections of the patterns (e.g. .*) is mapped to
|
|
the numbered positions in the responses, e.g. %1.
|
|
|
|
:type pairs: list of tuple
|
|
:param pairs: The patterns and responses
|
|
:type reflections: dict
|
|
:param reflections: A mapping between first and second person expressions
|
|
:rtype: None
|
|
"""
|
|
|
|
self._pairs = [(re.compile(x, re.IGNORECASE), y) for (x, y) in pairs]
|
|
self._reflections = reflections
|
|
self._regex = self._compile_reflections()
|
|
|
|
def _compile_reflections(self):
|
|
sorted_refl = sorted(self._reflections.keys(), key=len, reverse=True)
|
|
return re.compile(
|
|
r"\b({0})\b".format("|".join(map(re.escape, sorted_refl))), re.IGNORECASE
|
|
)
|
|
|
|
def _substitute(self, str):
|
|
"""
|
|
Substitute words in the string, according to the specified reflections,
|
|
e.g. "I'm" -> "you are"
|
|
|
|
:type str: str
|
|
:param str: The string to be mapped
|
|
:rtype: str
|
|
"""
|
|
|
|
return self._regex.sub(
|
|
lambda mo: self._reflections[mo.string[mo.start() : mo.end()]], str.lower()
|
|
)
|
|
|
|
def _wildcards(self, response, match):
|
|
pos = response.find('%')
|
|
while pos >= 0:
|
|
num = int(response[pos + 1 : pos + 2])
|
|
response = (
|
|
response[:pos]
|
|
+ self._substitute(match.group(num))
|
|
+ response[pos + 2 :]
|
|
)
|
|
pos = response.find('%')
|
|
return response
|
|
|
|
def respond(self, str):
|
|
"""
|
|
Generate a response to the user input.
|
|
|
|
:type str: str
|
|
:param str: The string to be mapped
|
|
:rtype: str
|
|
"""
|
|
|
|
# check each pattern
|
|
for (pattern, response) in self._pairs:
|
|
match = pattern.match(str)
|
|
|
|
# did the pattern match?
|
|
if match:
|
|
resp = random.choice(response) # pick a random response
|
|
resp = self._wildcards(resp, match) # process wildcards
|
|
|
|
# fix munged punctuation at the end
|
|
if resp[-2:] == '?.':
|
|
resp = resp[:-2] + '.'
|
|
if resp[-2:] == '??':
|
|
resp = resp[:-2] + '?'
|
|
return resp
|
|
|
|
# Hold a conversation with a chatbot
|
|
def converse(self, quit="quit"):
|
|
user_input = ""
|
|
while user_input != quit:
|
|
user_input = quit
|
|
try:
|
|
user_input = input(">")
|
|
except EOFError:
|
|
print(user_input)
|
|
if user_input:
|
|
while user_input[-1] in "!.":
|
|
user_input = user_input[:-1]
|
|
print(self.respond(user_input))
|