TWIT Coding 101 - Python Day 2 Homework

'''
This Python 2 program will build a list of favorite
cities based on input from the user, then compare the
cities to my list of favorite cities and output the
similarities. It then offers to delete a city from
the list and show the results. Uses while loops,
if-else and in statements and the isdigit() function.
'''

#Initialize my list with my favorite cities
myCities = ['New York','Los Angeles','London','Paris']

#Print out my favorite cities
print "My favorite cities are: ",myCities
print ""

#Ask the user for the number of cities they want to enter
yourCityCount = raw_input ("How many favorite cities do you have?: ")

#Validate that the input is a positive number
while not(yourCityCount.isdigit()):
  yourCityCount = raw_input ("How many favorite cities do you have? (NUMBERS ONLY): ")

#Change type to integer
yourCityCount = int(yourCityCount)

#Setup an empty list to be appended to by the user
yourCities=[]

#Loop through based on the user's number of cities and add their city to their list
#x is the loop counter
x=1
while x<yourCityCount+1:
  #Get the name of the city
  city = raw_input("Enter your number " + str(x) + " favorite city: ")

  #Make sure it's not a duplicate. If it's not, add it to the list and increase the loop counter
  if city in yourCities:
    print "You already entered", city + "! Please try again."
  else:
    x+=1
    yourCities.append(city)

#Output the user's list of cities
print ""
print "You have",str(yourCityCount) + " favorite cities: "
print yourCities
print ""

#Loop through the user's list of cities to see which cities are in common with my list
#Keep a count to display at the end
sameCityCount=0
for yourCity in yourCities:
  if yourCity in myCities:
    sameCityCount += 1
    print "We both like", yourCity + "."

#Display the number of cities in common, with correct plural noun
if sameCityCount > 0:
  if sameCityCount > 1:
    print "We have",str(sameCityCount) + " cities in common."
  else:
    print "We have",str(sameCityCount) + " city in common."
  print ""

#Offer to delete a city. Only attempt if there are cities
if yourCityCount > 0:

  #Get the name of the city to delete
  cityToDelete = raw_input("Which city would you like to delete?: ")

  #Only proceed if the city is in the list
  if cityToDelete in yourCities:

    #Loop back from the end of the list to prevent loop counter issues
    #x is the loop counter
    x=yourCityCount
    while x!=0:
      x-=1

      #If this item to delete, pop it
      if cityToDelete==yourCities[x]:
        yourCities.pop(x)

    #Print out the new list of cities
    print "I have deleted", cityToDelete + " from your list:", yourCities
  else:
    #Print an error message
    print "I couldn't find", cityToDelete + " in your list."

#Exit
raw_input ("Press Enter to Exit")