Python - 试图运行代码时什么都不会发生。我甚至没有得到一个错误

我想用Python创建一个小型博彩应用程序，当我尝试运行该程序时，什么也没有发生。我正在使用IDLE。这是我的代码：Python - 试图运行代码时什么都不会发生。我甚至没有得到一个错误

def bet(): 
    #balance = 100 
    x = 0 
    with open("bal.txt", "r") as f: 
     for l in f: 
      bal = (sum([int(a) for a in l.split()])) 
      while bal > 0: 
       print ("Your balance is: " + str(balance) + " credits.") 
       while x == 0: 
        print ("Enter the amount you would like to bet:") 
        bet = int(input()) 
        if bet > bal: 
         x = 0 
        elif bet < 0: 
         x = 0 
        else: 
         x = 1 
       print ("Pick a number between 1 and 20") 
       num = int(input()) 

       convbal = bal - bet 
       print ("Your bet is now locked in...") 
       print (" ") 
       print (" ") 

       import random 
       rannum = random.randint(1, 20) 
       print ("Your guess was: " + str(num)) 
       print (" ") 
       print ("The random number was: " + str(rannum)) 

       if rannum == num: 
        print ("WINNER") 
        bal = bal + (bet * 2) 
       else: 
        print ("LOSER") 
        print ("") 
        print ("")

这是我的结果收到壳：