While 循环中断

Question

我的 Python 代码包含一个无限循环。 如何终止无限循环？

colour = input("Which colour do you prefer? Y-R: ")
while colour not in {"Y", "R"}:
    print("Please, you have to choose only Y - R.")
    colour = input("Which colour do you prefer? Y-R: ")
    while colour in {"Y", "R"}:
      if colour == "Y":
         print("First player: Y")
         print("Second player: R")
      else:
         print("First player: R")
         print("Second player: Y")

Answer 1

使用break ：

colour = input("Which colour do you prefer? Y-R: ")
while colour not in ["Y", "R"]:
    print("Please, you have to choose only Y - R.")
    colour = input("Which colour do you prefer? Y-R: ")
    if colour in ["Y", "R"]:
      if colour == "Y":
         print("First player: Y")
         print("Second player: R")
         break
      else:
         print("First player: R")
         print("Second player: Y")
         break

然而，这是一个更好的解决方案：

colour = input("Which colour do you prefer? Y-R: ")       
 
while colour not in ["Y", "R"]:
    print("Please, you have to choose only Y - R.")
    colour = input("Which colour do you prefer? Y-R: ")


if colour == "Y":
    print("First player: Y")
    print("Second player: R")
else:
    print("First player: R")
    print("Second player: Y")

Answer 2

你真的只需要一个循环。

while True:
    colour = input("Which colour do you prefer? Y-R: ")
    
    if colour in {"Y", "R"}:
        first, second = "YR" if colour == "Y" else "RY"
        break

    print("Please, you have to choose only Y - R.")

print(f"First player: {first}")
print(f"Second player: {second}")