EOY programming test Y10- Vet Scenario

def displayName():
    """ This is a procedure which will ask the user for the name of their
        vet surgery, and then welcome them using the name they  have just
        input into the program.
    """
    surgery = input("What is the name of the Vet Surgery? > ")
    print("Welcome to the {0} Veterinary Surgery.".format(surgery))
    menuProgram() #Takes user back to subprogram selection.

#---------------------------------------------------------------------------------------

def checkUsernamePassword():
    """ This is a procedure which will ask the user for their username
        and password, and if they get a valid username and password
        they will get the message 'valid username and password', but if
        either the username or password are incorrect, the program will
        display 'invalid username and password'.
    """
    username = input("Please enter your username > ")
    password = input("Please enter your password > ")

    while username != "admin" or password != "ABC123*":
        print("Invalid username or password.")
        username = input("Please enter your username > ")
        password = input("Please enter your password > ")
    print ("Valid username and password.")

#---------------------------------------------------------------------------------------

def totalCost(mylist):
    """ This is a function which will calculate the total of a given
        list in a 'for' loop, and return the value to the main program.
    """
    cost = 0
    for element in mylist:
        cost = cost + element
    return cost

#---------------------------------------------------------------------------------------

def writeToFile():
    """ This is a function that allows the user to enter the firstname
        and surname of the owner, the name of the pet and the type of animal-
        this information will then be written to file.
    """
    answer = "Y" #Sets the initial guard variable to "Y" so that the program will enter
                 #the while loop at least once.
    while answer == "Y":
        animalfile = open("animals.txt","a") #Opens the file 'animals.txt' (or will create
                                             #a file of the same name if it doesn't already
                                             #exist) in append mode, so that data isn't overwritten
                                             #every time the program runs.

        firstname = input("Enter first name of owner > ") #Asking for the data to be appended onto file
        surname = input("Enter surname of owner > ")      # |
        petname = input("Enter pet name > ")              # |
        animaltype = input("Enter type of animal > ")     # v
        record = "{0} {1} {2} {3} \n".format(firstname, surname, petname, animaltype)
        #The variable 'record' is comprised of the 4 seperate variables created above- they are compiled
        #into the new variable 'record' so it only requires one 'fileName.write()' command as opposed
        #to four seperate ones.
        animalfile.write(record) #Writes the contents of the variable 'record onto the file'

        answer = input("Do you want to enter another customer Y/N ? > ") #Asks the user whether they would
        validList = ["Y","N"] #A list of valid answers                   #like to continue or not
        while answer not in validList: #Checks whether the users answer is in the valid list or not.
                                       #User will enter this while loop if it is not "Y" or "N"
            print("Invalid selection. Please choose again.")
            answer = input("Do you want to enter another customer Y/N ? > ")

    animalfile.close() #Closes the file so that other programs may access it.
    menuProgram() #Takes user back to subprogram selection.

#---------------------------------------------------------------------------------------

""" MAIN PROGRAM- Computer System for the Red Bank Veterinary Surgery
"""
print("LOGIN TO SYSTEM:") #Initial login- must do this before you can access other programs
checkUsernamePassword()

def menuProgram():
    """ This is the menu which enables you to choose which sub-program you would like to run.
    """
    print ("MENU:\n\n PRESS:\n\t1 for Welcome Message Program\n\t2 for Fluffy's Total Cost Program")
    print("\t3 for Patient Input Program\n\t0 to quit the program.")
    choice = input(" > ")

    if choice == "1":
        displayName()                                               # First Sub-Program

    elif choice == "2":
        fluffy = [10,5,8,20,8]                                      #Third Sub-
        totalcost = totalCost(fluffy)                               #Program
        print("Total cost for fluffy is £{0}.".format(totalcost))
        menuProgram()

    elif choice == "3":
        writeToFile()                                               #Fourth Sub-
                                                                    #Program
    elif choice == "0":
        print("Goodbye.")
    else:
        print("I didn't quite get that.")
        menuProgram()

menuProgram()