# function to add/subtract/multiply/divide 2 numbers
def do_calculation(command):
    print ("---" + command + " 2 integers---")
    in_num1 = int(input("Enter 1st number: "))
    in_num2 = int(input("Enter 2nd number: "))
    if command == "add" or command == "Add" :
        operator = "+"
        result = in_num1 + in_num2
    elif command == "subtract" or command == "Subtract":
        operator = "-"
        result = in_num1 - in_num2
    elif command == "multiply"  :
        operator = "*"
        result = in_num1 * in_num2
    elif command == "divide":
        operator = "/"
        if in_num2 != 0 :
            result = in_num1 / in_num2
        else:
            print("Cannot divide by 0")
            result = "***"
    print(str(in_num1) + operator + str(in_num2) + "=" + str(result))
# function to total or average a list of numbers
def calc_list(command):
    # Capture how many numbers you wish to average/total
    table = []
    table_total = 0
    how_many = input("how many numbers do you want to "+ command + "? ")
    how_many = int(how_many)
    # Loop that many times, capturing the numbers
    for item_number in range(how_many):
        item = input("what is number "+ str(item_number+1)+" ? ")
        item = float(item)
        table.append(item)
    # Keep a running total of the numbers
        table_total = table_total + item
    # display
    print("You have ", how_many, " numbers to " + command)
    for item in table :
        print(item)
    if command == "average" :
    # When the loop has finished divide the total by the number of numbers
        table_ave = table_total/how_many
        print("The average of your numbers is " + str(table_ave))
    elif command == "total":
        print("The total of your numbers is " + str(table_total))

finished = False
while finished == False :
    print ("I am Marvin, your personal bot.")
    users_name = input("What is your name? ")
    print ("Welcome " + users_name )
    command = input("How can I help:")
    # Check whether list or 2 integers
    if command in ["add","Add","subtract","Subtract","multiply","divide"]:
        do_calculation(command)
    elif command == "power":
        print ("--Raising a number to a power--")
        in_num1 = int(input("Enter number: "))
        in_num2 = int(input("Enter power: "))
        print(str(in_num1) + "**" + str(in_num2) + "=" + str(in_num1 ** in_num2))
    elif command == "average":
        calc_list(command)
    elif command == "total":
        calc_list(command)
    elif command == "discount":
    # get amount
        net = input("What is the bill amount:")
        net = float(net)
        # get percentage discount
        percen = input("What is the discount percentage (must be less than 100)")
        percen = float(percen)
    # print discount and amount to pay
        discnt = net * (percen/100)
        print("The discount on " + str(net) + " is "+ str(discnt))
        print("Amount to pay :" + str(net-discnt))
    elif command == "bye" :
        finished = True
    # Cater for unknown command
    else:
        print ("I dont understand '" + command + "'")