ValueError: too many values to unpack while trying to get a callback message from a chatbot

Question

I am beginner when it comes to using python and trying to build a chatbot by looking up basic function definition techniques from datacamp/others. However , getting this error when i am trying to call one of my function definitions. the error is on "response, phrase = match_rule(rules,message)" . Can someone help me out with this ?

rules ={'I want (.*)': ['What would it mean if you got {0}',
  'Why do you want {0}',
  "What's stopping you from getting {0}"]}

import re
import random
def match_rule(rules, message):
    response, phrase = "default", None


    # Iterate over the rules dictionary
    for pattern, responses in rules.iteritems():
        # Create a match object
        match = re.search(pattern,message)
        if match is not None:
            # Choose a random response
            response = random.choice(responses)
            if '{0}' in response:
                phrase = match.group(1)
    # Return the response and phrase
    return response.format(phrase)

def replace_pronouns(message):

    message = message.lower()
    if 'me' in message:
        # Replace 'me' with 'you'
        return re.sub('me','you',message)
    return message

def respond(message):
    # Call match_rule
    response, phrase = match_rule(rules,message)
    if '{0}' in response:
        # Replace the pronouns in the phrase
        phrase = replace_pronouns(phrase)
        # Include the phrase in the response
        response = response.format(phrase)
    return response

respond("I want a good code")

Error received :

ValueErrorTraceback (most recent call last)
<ipython-input-27-e6efc4eacb15> in <module>()
----> 1 print(respond("I want a good code"))

<ipython-input-21-4715e10175ce> in respond(message)
      1 def respond(message):
      2     # Call match_rule
----> 3     response, phrase = match_rule(rules,message)
      4     if '{0}' in response:
      5         # Replace the pronouns in the phrase

ValueError: too many values to unpack

Answer 1

Welcome to StackOverflow.

Your issue is here:

def respond(message):
    # Call match_rule
    print(f"{match_rule(rules,message)}")
    print("----")
    response, phrase = match_rule(rules,message)  # line with the issue
    if '{0}' in response:
        # Replace the pronouns in the phrase
        phrase = replace_pronouns(phrase)
        # Include the phrase in the response
        response = response.format(phrase)
    return response

if you call that, the return value of your match_rule(rules, message) is:

What's stopping you from getting a good code

it returns one value but you are trying to unpack two by coding:

response, phrase = match_rule(rules,message)

either change the return of match_rule to return two values or use one of the variables response or phrase, not both.