keep_running = True
count = 0

def do_calculation():

    # function to remove duplicated lines of code from add and subtract conditions
    print("Lets " + command + " some numbers.")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = float(input1)
    number2 = float(input2)

    if command == "add" or command == "Add":
        operator = "+"
        result = number1 + number2

    elif command == "subtract" or command == "Subtract":
        operator = "-"
        result = number1 - number2

    # print the result to the screen
    output = str(result)
    print(input1 + " operator " + input2 + " = " + output)


print ("Hi, I am Marvin, your personal bot.")
print()
users_name = input("Please enter your name : ")  #ask for users name

while keep_running == True:

#    print ("Hi, I am Marvin, your personal bot.")
#    print()
#    users_name = input("Please enter your name : ")  #ask for users name
    print ("Hi " + users_name + ".  I hope you enjoy using the bot.")
    print ("This bot will allow you to do simple mathematical procedures.")
    #command = input("So " + users_name + ", Would you like to 1 Add, 2 Subtract, 3 Divide, 4 Multiply, 5 find the Average of some numbers, or 6 create a Shopping List : ")
    command = input("So " + users_name + ", Would you like to Add, Subtract, Divide, Multiply, find the Average of some numbers, \n create a Shopping List or enter to end : ")
    # all numbers are floating point just in case decimals are needed

    if command == "add" or command == "Add" or command == "plus" or command == "Plus" :
        #add 2 numbers together

        do_calculation()


    elif command == "subtract" or command == "Subtract"  or command == "minus" or command == "Minus":
        #subtract 2 numbers from each other

        do_calculation()

        #print("Lets subtract some numbers from each other.")
        #input1 = input("Number 1> ")
        #input2 = input("Number 2> ")
        #number1 = float(input1)
        #number2 = float(input2)
        #result = number1 - number2
        #output = str(result)
        #print(input1 + " - " + input2 + " = " + output)


    elif command == "multiply" or command == "Multiply":
        #multiply 2 numbers by each other
        print("Lets multiply some numbers together.")
        input1 = input("Number 1> ")
        input2 = input("Number 2> ")
        number1 = float(input1)
        number2 = float(input2)
        result = number1 * number2
        output = str(result)
        print(input1 + " * " + input2 + " = " + output)


    elif command == "divide" or command == "Divide":
        #divide 2 numbers with each other
        print("Lets " + command + " some numbers.")
        input1 = input("Number 1> ")
        input2 = input("Number 2> ")
        number1 = float(input1)
        number2 = float(input2)
        result = number1 / number2
        output = str(result)
        print(input1 + " / " + input2 + " = " + output)


    elif command == "average" or command == "Average":
        #find the average of several numbers
        print("Lets find the " + command + " of some numbers.")
        print(command + " has just been implemented.  So here we go.")
        # Numcount = input("how many number would you like to average? > ")

        how_many = input("How many numbers? } ")
        how_many = int(how_many)
        Avelist = []

        total = 0
        for number_count in range (how_many):
            Avenumber = input("Enter number " + str(number_count) + " } ")
            total = total + float(Avenumber)
            Avelist.append(Avenumber)

        result =total / how_many
        result = result

        for Avenumber in Avelist:
            print(Avenumber)

        print("The average of the numbers above = " + str(result))


    elif command == "Shopping List" or command == "shopping list" or command == "Shopping list" or command == "shopping List":
        # shopping list creator
        shopping = []  #holds the shoopping items
        itemprice = [] # contains the item cost
        total_sum = 0  #variable for the total cost of the shopping items
        keep_shopping = True
        num = 0 #vriable for total number if items
        total_sum = 0
        while keep_shopping == True:

            #set up using a while statement to collect items until bye entered by user
            item = input("enter the item name or bye to finish : ")

            # ends the loop
            if item == "bye" or item == "Bye":
                keep_shopping = False
                continue

            shopping.append(item)
            price = input("enter the item price : ")
            itemprice.append(price)

            total_sum = total_sum + float((price))
            num = num +1
            print("Total shopping cost so far : " + str(total_sum) + " for : " + str(num) + " items")



        # prints the shopping list and total cost
        print ("Shopping list\n")
        for item_number in range(num):

            print (shopping[item_number] + "\t\t\t" + itemprice[item_number]  )

        print ("------------------------------------")
        print ("Total cost \t\t$" + str(total_sum)+ " for : " + str(num) + " items")


    else: #just in case they did not choose one of the options
        print("Sorry " + users_name + " but the bot can only Add, Subtract, Divide, Multiply, find the Average of numbers or creater a Shopping list")
        print("Cheers " + users_name)
    print()
    print("Hey " + users_name + ", thanks for using the Mathematics and Shopping list creator bot.  Cheers Marvin.")

    if command == "":
        keep_running = False