Implementing Abstraction

# Implementing Abstraction by offloading common / possibly repeating code into Functions
def do_calculation():
    print("lets " + command + " some numbers")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = int(input1)
    number2 = int(input2)
    if command == "add":
        result = number1 + number2
        operator = " + "
    elif command == "subtract":
        result = number1 - number2
        operator = " - "
    output = str(result)
    print(input1 + operator + input2 + " = " + output)

def do_average():
        #use a for loop storing each number into an array keeping a count (maybe)?
        #sum the members of the array and divide by the number of members
        #display the result

    numbers = []
    how_many = input("how many numbers would you like to find the average for? ")
    how_many = int(how_many)
    for item_number in range(how_many):
        display_number = item_number + 1
        item = input("what is your number " + str(display_number) + "? ")
        numbers.append(int(item))

#    print(numbers)

    count = 0
    for item in numbers:
        count = count + item
#       print(item)

    result = count / how_many
    print("No. of items in basket :  " + str(len(numbers)))
    print("The average of your  " +  str(len(numbers)) +  "  items is  " + str(result))


print("Would you like to add or subtract two numbers or find the average of multiple numbers?")
command = input("Enter 'add', 'subtract' or 'average' > ")
if command == "add" or command == "subtract" or command == "average":

    if command == "add":
        do_calculation()

    elif command == "subtract":
        do_calculation()

    elif command == "average":
        do_average()


else:
    print("Try again and enter 'add', 'subtract' or 'average ")
    print("Bye")