for循環內的Python While循環在值無效時繼續重復

Question

這是我的代碼：

for i in range(1, 5):
    try:
        grade = int(input("Please enter {}'s grade for practical assessment {}: ".format(name, i)))
        while (grade < 0 and grade > 40):
            print("That is not a valid grade.")
            continue
    except ValueError:
        print("That is not a valid value.")
        continue

我的問題是，如果輸入錯誤的輸入，如何檢查成績是否在范圍內，並使循環重復。 當我嘗試運行該程序並輸入一個超出范圍的輸入時，它將轉到下一個評估編號，而不是再次嘗試直到正確為止。

Answer 1

您可以使用類似以下內容的代碼，該代碼使用while True循環以及try statement and except clause來確定用戶是否輸入了有效成績：

names = ["Adam", "Bob", "Chloe"] # Example list of names

for name in names:
  for i in range(1, 5):
    while True:
      try:
        grade = int(input("Please enter {}'s grade for practical assessment {}: ".format(name, i)))
        if not (0 <= grade <= 40):
          raise ValueError()
      except ValueError:
        print("Error: Please enter a grade between 0 and 40")
      else:
        break

用法示例：

Please enter Adam's grade for practical assessment 1:  a
Error: Please enter a grade between 0 and 40
Please enter Adam's grade for practical assessment 1:  -1
Error: Please enter a grade between 0 and 40
Please enter Adam's grade for practical assessment 1:  10
Please enter Adam's grade for practical assessment 2:  4
Please enter Adam's grade for practical assessment 3:
...

在這里嘗試！