Python if语句不能在函数内部工作

当我不使用again函数并在相应位置复制和粘贴所有代码时,它可以正常工作。不过,当我使用“再次播放”功能时,“再次播放?”问题被提出,但if语句被忽略,导致while循环无休止地继续。我试过使用global函数,但在第二次输入guess时,它出现了TypeError:“str”对象不可调用。

import random

def guess():
    global num
    num = random.randint(1,3)
    guessat  = input("Out of 1 to 3, which number do you guess? ")
    return(guessat)

def again():
    global again
    again = input("Play again? ")
    if again in ["y","yes"]:
        guessing = True
    else:
        guessing = False

print("Welcome to Guess the Number!")

guessing = True

while guessing:
    guessy = guess()
    guessy = int(guessy)
    if guessy == num:
        print("You got it right!")
        again()

    elif guessy != num:
        print("Wrong number!")
        again()
quit()