Python 3嵌套While循环

Question

我已经创建了一个函数来要求用户输入输入一天中工作的小时数，整个事情返回正确的，除了如果输入一个不正确的值，它不会显示其错误信息如果输入的值小于零，则它会再次输入。

def hours_for_days(week_no,day): 
    i = -1 
    input_string = "Enter number of hours for week " + str(week_no) + " " + day + ": " 
    while i <0 
    work_time = rawinput(input_string) 
    try: 
     i = int(work_time) 
    except ValueError: 
     print("Enter a number: ") 
    else: 
     while 24 < i 
     work_time = rawinput(input_string) 
     try: 
     i = int(work_time) 
     except ValueError: 
     print("Enter a number: ") 
     else: 
     if i < 0 
      print("Enter a number between 0 and 24") 
     if i > 24 
      print("Enter a number between 0 and 24") 

Answer 1

您可以添加：

while 1: 
    work_time = rawinput(input_string) 
    try: 
     i = int(work_time) 
     if not (0 <= i <= 24): 
      raise(IndexError) 
     break 
    except ValueError: 
     print("Enter a number: ") 
    except IndexError: 
     print("Number must be between 0 and 24")