This is the error:

plane_ride_cost('Charlotte') returned None instead of the correct value 183

This is my code:

Vacation Trip Spending Estimator

# Cost of Hotel Stay

print "Nyce Travel Agency Trip Spending Estimator"

nights = int(raw_input("How many night will you being staying? "))

def hotel_cost(nights):

return 140 * nights

# Cost of plane

print "Plane Ticket Prices"

city = raw_input("What city are you visiting? ")

def plane_ride_cost(city):

if type(city) == str:

return

if city == "Charlotte":

return 183

if city == "Tampa":

return 220

if city == "Pittsburgh":

return 222

if city == "Los Angeles":

return 475

else:

return "City not found"

# Cost of Rental Car

days = raw_input("How many days will you need a rental car? ")

def rental_car_cost(days):

cost = days * 40

if type(days) == int:

return rental_car_cost2(days)

def rental_car_cost2(days):

cost = days * 40

if days >= 7:

return (cost) - 50

elif days >= 3:

return (cost) - 20

else:

return (cost)

def trip_cost(city, days, nights):

return sum(rental_car_cost(days), hotel_cost(nights), plane_ride_cost(city))