使用两个函数的货币兑换器

Question

我试图在一个程序中使用两个函数来制作一个货币兑换器，但由于某些原因，我的程序要么得到这个错误。

line 23, in Input1
    print(amount+"Won equals to "+totalamount+" USD")
TypeError: unsupported operand type(s) for +: 'float' and 'str'

或者在输入 "选项 "和 "金额 "后没有打印任何东西。这是我的程序。

print("Please choose which currency you want to convert:")
print("A - Korean Won to US Dollar (Exchange Rate: 0.000905)")
print("B - Korean Won to Euro (Exchange Rate: 0.000807350908)")
print("C - Korean Won to Japanese Yen (Exchange Rate: 0.0919061643)")
print("D - Korean Won to Chinese RMB (Exchange Rate: 0.00603703605)")
print("E - Quit")

usd = 0.000905
eur = 0.000807350908
yen = 0.0919061643
rmb = 0.00603703605

def main():
    option =input("Enter your option: ")
    if option== "E":
        exit()
    amount =float(input("Enter the amoutn in Korean Won: "))
    Input1(option, amount)

def Input1(option,amount):
    if option == "A":
        totalamount = (amount * usd)
        print(amount+"Won equals to "+totalamount+" USD")
    elif option== "B":
        totalamount = (amount * eur)
        print (amount+"Won equals to "+totalamount+" Euro")
    elif option== "C":
        totalamount = (amount * yen)
        print (amount+"Won equals to "+totalamount+" Yen")
    elif option== "D":
        totalamount = (amount * rmb)
        print (amount+"Won equals to "+totalamount+" Chinese RMB")
    else:
            print("You entered an invalid input.")
    return option,amount

main()

你们能不能给我一些提示来解决我的程序？我还在学习python，任何帮助将是非常感激的。非常感谢您

Answer 1

你只需要把当前浮动的金额和totalamount变量打成字符串就可以了

print(str(amount)+"Won equals to "+str(totalamount)+" USD")

或者使用你使用的格式功能

print("{} Won equals to {} USD ".format(amount, totalamount))

而且我认为格式功能是更好的选择

Answer 2

你必须转换 amount 和 totalamount 的字符串，然后再将其用于 print() 作为带+的字符串。你可以使用 str() 方法。

print(str(amount)+"Won equals to "+str(totalamount)+" USD")

Answer 3

使用f-string代替字符串连接，它将为你处理转换。

print(f"{amount} won equals to {totalamount} USD")

如果你真的想自己做转换，它看起来会像这样。

print(str(amount) + "Won equals to " + str(totalamount) + " USD")

(编辑) 为了回答评论中的问题，把你的... main() 功能，以。

def main():
    while True:
        option = input("Enter your option: ")
        if option== "E":
            break
        amount = float(input("Enter the amount in Korean Won: "))
        Input1(option, amount)