Chatbot example functions in python + sqlite3 for chatbot test

find_hotels.py

import sqlite3 

# Define find_hotels()
def find_hotels(params):
    # Create the base query
    query = 'SELECT * FROM hotels'
    # Add filter clauses for each of the parameters
    if len(params) > 0:
        filters = ["{}=?".format(k) for k in params]
        query += " WHERE " + " and ".join(filters)
    # Create the tuple of values
    t = tuple(params.values())
    
    # Open connection to DB
    conn = sqlite3.connect("hotels.db")
    # Create a cursor
    c = conn.cursor()
    # Execute the query
    c.execute(query,t)
    # Return the results
    print(c.fetchall())


# Create the dictionary of column names and values
params = {"area": "south" , "price": "lo"}

# Find the hotels that match the parameters
print(find_hotels(params))

find_negated.py

# Define negated_ents()
def negated_ents(phrase):
    # Extract the entities using keyword matching
    ents = [e for e in ["south", "north"] if e in phrase]
    # Find the index of the final character of each entity
    ends = sorted([phrase.index(e) + len(e) for e in ents])
    # Initialise a list to store sentence chunks
    chunks = []
    # Take slices of the sentence up to and including each entitiy
    start = 0
    for end in ends:
        chunks.append(phrase[start:end])
        start = end
    result = {}
    # Iterate over the chunks and look for entities
    for chunk in chunks:
        for ent in ents:
            if ent in chunk:
                # If the entity is preceeded by a negation, give it the key False
                if "not" in chunk or "n't" in chunk:
                    result[ent] = False
                else:
                    result[ent] = True
    return result  

# Check that the entities are correctly assigned as True or False
for test in tests:
    print(negated_ents(test[0]) == test[1])

respond.py

# Define respond()
def respond(message):
    # Extract the entities
    entities = interpreter.parse(message)["entities"]
    # Initialize an empty params dictionary
    params = {}
    # Fill the dictionary with entities
    for ent in entities:
        params[ent["entity"]] = str(ent["value"])

    # Find hotels that match the dictionary
    results = find_hotels(params)
    # Get the names of the hotels and index of the response
    names = [r[0] for r in results]
    n = min(len(results),3)
    # Select the nth element of the responses array
    return responses[n].format(*names)
    
print(respond("I want an expensive hotel in the south of town"))
  

respond_with_slot.py

# Define a respond function, taking the message and existing params as input
def respond(message, params):
    # Extract the entities
    entities = interpreter.parse(message)["entities"]
    # Fill the dictionary with entities
    for ent in entities:
        params[ent["entity"]] = str(ent["value"])

    # Find the hotels
    results = find_hotels(params)
    names = [r[0] for r in results]
    n = min(len(results), 3)
    # Return the appropriate response
    return responses[n].format(*names), params

# Initialize params dictionary
params = {} 

# Pass the messages to the bot
for message in ["I want an expensive hotel", "in the north of town"]:
    print("USER: {}".format(message))
    response, params = respond(message, params)
    print("BOT: {}".format(response))