how to repeat code in python until a condition is met

a = 1
b = 1
while (a<10):
  print ('Iteration',a)
  a = a + 1
  b = b + 1
  if (b == 4):
    break
print ('While loop terminated')

def main():
    while True:
        again = raw_input("Would you like to play again? Enter y/n: ")

        if again == "n":
            print ("Thanks for Playing!")
            return
        elif again == "y":
            print ("Lets play again..")
        else:
            print ("You should enter either \"y\" or \"n\".")

if __name__ == "__main__":
    main()