Python—有人能解释一下为什么我总是得到正确的输出，但它总是说；无”；在它下面

尝试在第一个代码框中测试我的函数，我不断得到我想要的正确输出，但由于某种原因，它下面显示“无”，正如您在第二个代码框中看到的，然而，Colab没有指示任何错误，但我必须测试它的第三个代码框中的程序不断给我错误消息-“有些地方不太正确：请尝试检查此处的所有测试用例，并确保您的函数适用于所有测试用例。”帮助

我正在用这个代码测试它

    # Run this cell to get feedback on your answer
def test_speeding_ticket(answer):

  student_score = 1

  cases = [
      (35, 55, "ok"),
      (56, 55, "grace"),
      (62, 55, "grace"),
      (73, 55, "ticket"),
      (56, 35, "ticket"),
      (34, 35, "ok"),
      (42, 35, "grace"),
  ]

  for case in cases:
    ref = case[2]
    if answer(case[0], case[1]) != ref:
      student_score = 0

  if student_score == 1:
    print("Correct, great job!")
  else:
    print("Something's not quite right: try checking all the test cases here and make sure your 
function works for all of them")

test_speeding_ticket(speeding_ticket)

---

您使用的是

print

，它不会

返回它打印的内容，而是返回
None
。因此，当您
打印函数（
\u answer
）的结果时，也就是
None
。将函数更改为：

def speeding_ticket(speed, limit):
  if speed <= limit:
    _answer = "ok"  # No print
  elif speed >= limit and speed <= limit + 9:
    _answer = "grace"  # No print
  else:
    _answer = "ticket"  # No print
  return _answer

def超速罚单（速度、限制）：
如果速度=限制和速度，问题在于
print
返回
None
。将
print
赋值给变量将赋值
None

def超速罚单（速度、限制）：
如果speed=limit和speed@python\u user：他们真的应该让他们的函数返回正确的东西，而不是在内部打印。谢谢！所以本质上我不能真正将print（）函数分配给变量？
所以本质上我不能真正分配print（）函数到一个变量？
这应该做什么？要么你
打印
，要么你
返回
。或者两者都做。但是不要
返回打印
@quiteplatypus 123：我的意思是，你可以；毕竟你做了。只是它返回
无
，所以它没有用处。如果你想
打印
并赋值，只需赋值，then
打印您分配给它的内容。
    # Run this cell to get feedback on your answer
def test_speeding_ticket(answer):

  student_score = 1

  cases = [
      (35, 55, "ok"),
      (56, 55, "grace"),
      (62, 55, "grace"),
      (73, 55, "ticket"),
      (56, 35, "ticket"),
      (34, 35, "ok"),
      (42, 35, "grace"),
  ]

  for case in cases:
    ref = case[2]
    if answer(case[0], case[1]) != ref:
      student_score = 0

  if student_score == 1:
    print("Correct, great job!")
  else:
    print("Something's not quite right: try checking all the test cases here and make sure your 
function works for all of them")

test_speeding_ticket(speeding_ticket)

def speeding_ticket(speed, limit):
  if speed <= limit:
    _answer = "ok"  # No print
  elif speed >= limit and speed <= limit + 9:
    _answer = "grace"  # No print
  else:
    _answer = "ticket"  # No print
  return _answer