def preference_extractor(self, user_input):
"""
Parameters
----------
user_input : str
user utterance.
Returns
-------
user_preferences : list
list of user preferences extracted from utterance.
p[0] for the area, p[1] for the price range and p[2] for the food type
"""
user_preferences = [
0 for i in range(3)
] #the preferences are stored in a list of three elements, p[0] for the area, p[1] for the price range and p[2] for the food type
s = self.stopwords_removal(user_input)
user_preferences = self.no_preference(
user_input,
user_preferences) #check if user indicated no preference
#keyword matching for the area
for i in s:
for j in self.area:
if i == j:
user_preferences[0] = j
if (('north' and 'american' in s) and (s.count('north')) > 1):
user_preferences[0] = 0
#keyword matching for the price range
for i in s:
for j in self.price_range:
if i == j:
user_preferences[1] = j
#keyword matching for the food type
for i in s:
for j in self.food_types:
if i == j:
user_preferences[2] = j
elif ('asian' and 'oriental' in s):
user_preferences[2] = 'asian oriental'
elif ('modern' and 'european' in s):
user_preferences[2] = 'modern european'
elif ('north' and 'american' in s):
user_preferences[2] = 'north american'
#In case the area has been mispelt
if (user_preferences[0] == 0):
d = {}
l = []
z = ['south', 'centre', 'west', 'east', 'north']
for i in s:
for j in z:
if (dt(i, j) <= 2) and i != 'want' and i != 'eat':
d[j] = dt(i, j)
for i in d.values():
l.append(i)
if len(l) > 0:
k = min(l)
key_list = list(d.keys())
val_list = list(d.values())
if k <= 2:
user_preferences[0] = key_list[val_list.index(k)]
#In case the price range has been mispelt
if (user_preferences[1] == 0):
d = {}
l = []
d = {}
l = []
for i in s:
for j in list(set(self.price_range)):
if (dt(i, j) <= 3):
d[j] = dt(i, j)
for i in d.values():
l.append(i)
if len(l) > 0:
k = min(l)
key_list = list(d.keys())
val_list = list(d.values())
if k <= 2:
user_preferences[1] = key_list[val_list.index(k)]
#In case the food type has been mispelt
#thresolds for Levenshtein distances might need to be better tuned for each preference
if (user_preferences[2] == 0):
d = {}
l = []
for i in s:
for j in list(set(self.food_types)):
if (dt(i, j) <= 2):
d[j] = dt(i, j)
elif (dt('asian', i) <= 2 or dt('oriental', i) <= 2 in s):
d['asian oriental'] = min(
[dt('asian', i), dt('oriental', i)])
elif (dt('modern', i) <= 2 or dt('european', i) <= 2 in s):
d['modern european'] = min(
[dt('modern', i),
dt('european', i)])
elif (dt('north', i) <= 2 or dt('american', i) <= 2 in s):
if ('north' and 'american' in s):
d['north american'] = min(
[dt('north', i),
dt('american', i)])
for i in d.values():
l.append(i)
if len(l) > 0:
k = min(l)
key_list = list(d.keys())
val_list = list(d.values())
if k <= 3:
user_preferences[2] = key_list[val_list.index(k)]
return user_preferences
def dialogue(self, user_input, state, user_preferences):
"""
recursive state transition function.
Parameters
----------
user_input : str
DESCRIPTION.
state : str
State of the system.
user_preferences : list
list of user preferences (area,price,foodtype).
Returns
-------
None.
"""
if user_input in [
"configure formal", "configure delay", "configure informal",
"configure no delay"
]:
self.configure(user_input)
user_input = ""
self.dialogue(user_input, state, user_preferences)
time.sleep(self.delay)
self.statelog.append(
[user_input, state]
) #tuple of user utterance and its associated state. We use this to keep track of state jumps.
if state == "exit":
print("Dialog Agent: " +
random.choice(self.responses.get("Goodbye")))
return
if state in ("init"):
user_preferences = [0, 0, 0]
user_input = input("Dialog Agent: " +
random.choice(self.responses.get("Welcome")) +
"User: "******"inform", "reqalts", 'hello'):
extracted_preferences = self.preference_extractor(user_input)
for i, d in enumerate(user_preferences):
if d == 0:
user_preferences[i] = extracted_preferences[i]
state = "fill_blanks" #if more slots to be filled
self.suggestions = self.lookup(user_preferences)
if (len(self.suggestions) == 0) or (len(self.suggestions) == 1):
state = "answer" #if there is none or 1 restaurant to suggest
self.dialogue(user_input, state, user_preferences)
return
if state == "fill_blanks": #ask user for area/foodtype/pricerange
grounding = self.grounding(user_preferences)
if user_preferences[0] == 0:
user_input = input("Dialog Agent: " + grounding +
random.choice(self.responses.get("Area")) +
"User: "******"area" not in user_input:
user_input += " area"
if "dont care" in user_input:
user_input = 'any area'
elif user_preferences[1] == 0:
user_input = input("Dialog Agent: " + grounding +
random.choice(self.responses.get("Price")) +
"User: "******"price" not in user_input:
user_input += " price"
if "dont care" in user_input:
user_input = 'any price'
elif user_preferences[2] == 0:
user_input = input("Dialog Agent: " + grounding +
random.choice(self.responses.get("Food")) +
"User: "******"food" not in user_input:
user_input += " food"
if "dont care" in user_input:
user_input = 'any food'
else:
state = 'ask_extra_preferences'
self.dialogue(user_input, state, user_preferences)
return
if state == 'ask_extra_preferences':
state = self.ask_extra_preferences(user_preferences)
self.dialogue(user_input, state, user_preferences)
return
if state == "confirmpreferences":
user_input = input(
"Dialog Agent: " +
random.choice(self.responses.get("AffirmPreferences")).format(
user_preferences[0], user_preferences[1],
user_preferences[2]) + "User: "******"answer"
elif accept is False:
state = "inform"
user_input = ""
user_preferences = [0, 0, 0]
elif accept == "reqalts":
user_preferences = [0, 0, 0]
else:
state = "accept"
self.dialogue(user_input, state, user_preferences)
return
if state == "answer":
if self.suggestions: #found at least 1 restaurant
user_input = input("Dialog Agent: " +
self.suggest_restaurant() + "User: "******"ack", "affirm"]:
state = "goodbye"
elif state in ["reqalts", "reqmore", "deny", "negate"]:
state = "answer"
else: #no restaurants found. Search for alternatives
alternatives = self.get_alternative_restaurants(
self.alternative_preferences(
user_preferences)) #offer alternatives
if len(alternatives) == 1: #found 1 alternative
print("Dialog Agent: " +
random.choice(self.responses.get("NoOptions")) +
"Let me look for an alternative for you...\n")
self.suggestions = alternatives
self.recommendation = self.suggestions[0]
user_input = input("Dialog Agent: " +
self.suggest_restaurant() + "User: "******"goodbye"
elif alternatives: #found multiple alternatives
print("Dialog Agent: " +
random.choice(self.responses.get("NoOptions")) +
"Here is a list of alternatives:")
for a in alternatives:
print("Dialog Agent: " + self.get_restaurant_info(a))
user_input = input(
"Dialog Agent: " +
'Would you like to choose one (1) or change your preferences(2)?\n'
+ "User: "******"1":
user_input = input(
"Dialog Agent: " +
"Which one would you like to choose?\n" + "User: "******"thankyou"
elif user_input == "2":
user_preferences = [0, 0, 0]
state = 'inform'
elif user_input == "exit":
state = 'exit'
else:
print("Dialog Agent: " +
"Please choose one of the two options")
else: #didnt find any alternative
print("Dialog Agent: " +
random.choice(self.responses.get("NoOptions")))
user_preferences = [0, 0, 0]
state = 'inform'
user_input = ""
self.dialogue(user_input, state, user_preferences)
return
if state in ["reqalts", "thankyou", "goodbye", "reset"]:
user_input = input(
"Dialog Agent: " +
self.get_restaurant_contacts(self.recommendation) +
". Would you like to finish here?\n" + "User: "******"ack", "affirm")):
state = "exit"
else:
state = "init"
self.dialogue(user_input, state, user_preferences)
return
if state == "repeat":
try:
user_input = self.statelog[len(self.statelog) - 3][0]
state = self.statelog[len(self.statelog) - 3][1]
except IndexError:
print("Dialog Agent: " +
"Nowhere to go back, starting again\n")
state = "init"
self.dialogue(user_input, state, user_preferences)
return
else:
print(
"Dialog Agent: " +
"I could not understand that, could you phrase it differently?"
) #statelog[len(statelog) + 1][0]
state = self.statelog[len(self.statelog) - 2][1]
self.dialogue(user_input, state, user_preferences)
return