4.9 reusing code

finished = False
def do_calculation():
            print("Let us " + 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=" - "
            else:
                print(command+" is not a valid answer. I do not know if I should add, subtract or calculate an average. Please Try again.")
            output=str(result)
            print(input1+operator+input2+" = "+output)

while finished == False:
    print("Hi, I am the bot that Sue created.")
    print("Let's get started.")
    users_name=input("What is your name? ")
    print("Welcome "+users_name)
    command=input("Please type add, subtract, or mean to calculate the average. Type bye if you would like to leave the program.>")
    if command=="bye":
        finished=True
    elif command=="mean":
        how_many=input("How Many Numbers Do You Want to Average?>")
        how_many=int(how_many)
        total=0
        for number_count in range(how_many):
            number=input("Enter number "+str(number_count)+"> ")
            total = total + int(number)
        result=total/how_many
        print("The average = "+str(result))
    else:
        do_calculation()

    if finished==False:
        shopping=[]
        count=0
        how_many=input(users_name+", how many items do you have on your shopping list? ")
        how_many=int(how_many)
        for item_number in range(how_many):
            item=input("What is the item number "+str(item_number)+" ? ")
            shopping.append(item)
        for item in shopping:
            print(item)
            count=count+1
        print(count)
        print (len(shopping))
        strcount=str(count)
        print (users_name+", you have "+strcount+" items in your shopping list.")