话不多说,奉上代码: #倒计时 def count_down(i): if i <= 0: return else: print(str(i)) count_down(i - 1) #求阶乘 def factorial(x): if x == 1: return 1 return x * factorial(x - 1) #斐波那契数列 def fabonacci(i): if i == 1 or i == 2: return 1 elif i >= 3: return fabonacci(i…