如何正確定義 Python 中的 function ？

Question

好吧，我正在按照教程編寫此模擬，最后，我在錯誤中得到了這個（這些是一些變量）：

num_cashiers, num_servers, num_ushers = get_user_input() NameError: name 'get_user_input' 未定義

當我在 class 中將其定義為 function 時，所有內容都寫入其中。 幫助！

這是一些代碼：

        def get_user_input():
        num_cashiers = input("Enter no. of cashiers working: ")
        num_servers = input("Enter no. of servers working: ")
        num_ushers = input("Enter no. of ushers working: ")

        # Now, brace yourself! Do try to understand this stuff

        if all(str(i).isdigit() for i in params): # Check if input is valid
            params = [int(x) for x in params]
        else:
            print("Could not parse input. The simulation will use default values: ",
                  "\n1 cashier, 1 server, 1 usher")

            params = [1, 1, 1]
        return params

    def main():
        # Setup
        random.seed(42)
        num_cashiers, num_servers, num_ushers = get_user_input() 

        # Run the Simulation
        env = simpy.Environment()
        env.process(run_theater(env, num_cashiers, num_servers, num_ushers))
        env.run(until=90)

        # View the results
        mins, secs = get_average_wait_time(wait_times)
        print(
            "Running simulation...",
            f"\nThe average wait time is {mins} minutes and {secs} seconds.",
            )

    if __name__ == '__main__':
        main()

Answer 1

實際上，您的腳本中存在縮進錯誤。 正確一個

def get_user_input():
    num_cashiers = input("Enter no. of cashiers working: ")
    num_servers = input("Enter no. of servers working: ")
    num_ushers = input("Enter no. of ushers working: ")
       .......

Answer 2

你的縮進不正確。

def get_user_input():
  num_cashiers = input("Enter no. of cashiers working: ")
  num_servers = input("Enter no. of servers working: ")
  num_ushers = input("Enter no. of ushers working: ")

  # Now, brace yourself! Do try to understand this stuff

  if all(str(i).isdigit() for i in params): # Check if input is valid
      params = [int(x) for x in params]
  else:
      print("Could not parse input. The simulation will use default values: ",
            "\n1 cashier, 1 server, 1 usher")

      params = [1, 1, 1]
  return params

def main():
  # Setup
  random.seed(42)
  num_cashiers, num_servers, num_ushers = get_user_input() 

  # Run the Simulation
  env = simpy.Environment()
  env.process(run_theater(env, num_cashiers, num_servers, num_ushers))
  env.run(until=90)

  # View the results
  mins, secs = get_average_wait_time(wait_times)
  print(
      "Running simulation...",
      f"\nThe average wait time is {mins} minutes and {secs} seconds.",
      )

if __name__ == '__main__':
    main()

我還想提醒您，如果您運行此代碼，您將收到一條錯誤消息

UnboundLocalError：分配前引用的局部變量“params”

因為您甚至在聲明它之前就使用了params

Answer 3

好的，您應該首先分配參數，然后檢查用戶輸入是否正確，如下所示：

def get_user_input():
        num_cashiers = input("Enter no. of cashiers working: ")
        num_servers = input("Enter no. of servers working: ")
        num_ushers = input("Enter no. of ushers working: ")

        params = [num_cashiers,num_servers,  num_ushers] # <------ I've added this line

        if all(str(i).isdigit() for i in params):
            params = [int(x) for x in params]
        else:
            print("Could not parse input. The simulation will use default values: ",
                  "\n1 cashier, 1 server, 1 usher")

            params = [1, 1, 1]
        return params

當然，你的縮進是不正確的。 我希望你知道