自己寫個小程式玩，程式碼實現：
 

def findMinAndMax(L):
    if len(L) == 0:
        return (None, None)
    else:
        mi = L[0]
        ma = L[0]
        for n in L:
            if n <= mi:
                mi = n
            elif n >= ma:
                ma = n
        return (mi, ma)

測試程式碼：

if findMinAndMax([]) != (None, None):
    print('測試失敗!0')
elif findMinAndMax([7]) != (7, 7):
    print('測試失敗!1')
elif findMinAndMax([7, 1]) != (1, 7):
    print('測試失敗!2')
elif findMinAndMax([7, 1, 3, 9, 5]) != (1, 9):
    print('測試失敗!3')
else:
    print('測試成功!')

最後執行結果：

測試成功!