我只是个python新手，有人能帮我写代码吗？我为这个问题困了一个星期
下面是我代码：

price = {
    "Espresso": 5.80,
    "Americano": 6.90,
}

currency = "$"

print ("welcome coffee machine!\t")
name = input ("can i get your name?\n")

print ("what do you like to order mr/ms " + name + "\n"  )

menu = ("Espresso, Americano")

print (menu)
menu = (input())

quantity = input("How many " + menu + " would you like?\n")
quantity = str(input())

#im stuck at here! T_T 
if menu == "Espresso" :
    price = 5.80
    total = quantity * price
    quantity.append(quantity)
    price.append(price)
    print(total)

elif menu == "Americano":
    price = 6.90
    total = quantity * price
    quantity.append(quantity)
    price.append(price)
    print(total)

else:
     menu()

#invoice receipt

print("Thank you for order " + name + ", please wait your " + menu + " at counter\n")

希望某人/某人能帮我解决这个问题