如何使用pytest测试get_date函数？

huangapple
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英文:

How do I test a get_date function using pytest?

问题

  1. 我有一个名为get_date的函数，在一个项目中，我被要求使用pytest来测试它。

def get_date(string):
try:
date_str = input(string)
date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
return date
except ValueError:
print("Please enter a date in the YYYY-MM-DD format")
return get_date(string)

  2. 我之前有：

def get_date(string):
while True:
try:
date_str = input(string)
date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
return date
except ValueError:
print("Please enter a date in the YYYY-MM-DD format")
raise

def test_get_date(monkeypatch):
inputs = [
"12/06/2023",
"12-06-2023",
"2023/06/12",
"2023/17/87",
"hello",
"2023-06-12",
]
input_values = iter(inputs)
monkeypatch.setattr("builtins.input", lambda _: next(input_values))

  1. # Test first input ("12/06/2023")
  2. with pytest.raises(ValueError):
  3.     get_date("Date (YYYY-MM-DD): ")
  5. # Test second input ("12-06-2023")
  6. with pytest.raises(ValueError):
  7.     get_date("Date (YYYY-MM-DD): ")
  9. # Test third input ("2023/06/12")
  10. with pytest.raises(ValueError):
  11.     get_date("Date (YYYY-MM-DD): ")
  13. # Test fourth input ("hello")
  14. with pytest.raises(ValueError):
  15.     get_date("Date (YYYY-MM-DD): ")
  17. # Test fifth output ("2023-06-12")
  18. assert get_date("Date (YYYY-MM-DD): ") == datetime.date(2023, 6, 12)
  2. 这个问题是，当引发ValueError时，程序会崩溃，而不是重新提示用户输入新的内容，这是绝对不能发生的。
  4. 我考虑将该函数更改为一个is_date函数，该函数将返回一个布尔值，但这将涉及更改整个程序，而我不打算这样做，因为一切都运行得很正常。
  6. 此外，这是一个无返回值的函数，因此我无法使用通常的assert方法。我做了一些研究，发现了这种iter方法，但我不确定这是否是最佳方法。
  8. 我真的希望您能帮助我解决这个问题
英文:

I got this function called get_date in a project and I'm requested to test it via pytest.

  1. def get_date(string):
  2.     try:
  3.         date_str = input(string)
  4.         date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  5.         return date
  6.     except ValueError:
  7.         print("Please enter a date in the YYYY-MM-DD format")
  8.         return get_date(string)

I previously had:

  1. def get_date(string):
  2.     while True:
  3.         try:
  4.             date_str = input(string)
  5.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  6.             return date
  7.         except ValueError:
  8.             print("Please enter a date in the YYYY-MM-DD format")
  9.             raise
  1. def test_get_date(monkeypatch):
  2.     inputs = [
  3.         "12/06/2023",
  4.         "12-06-2023",
  5.         "2023/06/12",
  6.         "2023/17/87",
  7.         "hello",
  8.         "2023-06-12",
  9.     ]
  10.     input_values = iter(inputs)
  11.     monkeypatch.setattr("builtins.input", lambda _: next(input_values))
  13.     # Test first input ("12/06/2023")
  14.     with pytest.raises(ValueError):
  15.         get_date("Date (YYYY-MM-DD): ")
  17.     # Test second input ("12-06-2023")
  18.     with pytest.raises(ValueError):
  19.         get_date("Date (YYYY-MM-DD): ")
  21.     # Test third input ("2023/06/12")
  22.     with pytest.raises(ValueError):
  23.         get_date("Date (YYYY-MM-DD): ")
  25.     # Test fourth input ("hello")
  26.     with pytest.raises(ValueError):
  27.         get_date("Date (YYYY-MM-DD): ")
  29.     # Test fifth output ("2023-06-12")
  30.     assert get_date("Date (YYYY-MM-DD): ") == datetime.date(2023, 6, 12)

The issue with this is that when the ValueError is raised the program crashes instead of re-prompting the user for new input, which is something that really can't happen.

I thought of changing the function to a is_date function that would return a bool, but that would involve changing the whole program, which is something I'm not looking for since everything works just fine.

Also, this is a void function and because of it I can't use the usual assert method. I did some research and found this iter method which I'm not sure is the optimal way to do so.

I really hope you can help me solve this problem

答案1

得分: 1

通过添加raise，你会在打印错误消息后重新引发ValueError，从而导致程序崩溃。

因此，如果你希望程序要求用户重新输入数据，需要在get_date函数中删除raise语句。

希望这有所帮助

以下是整个代码：

  1. import datetime
  2. import pytest
  4. def get_date(string):
  5.     while True:
  6.         try:
  7.             date_str = input(string)
  8.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  9.             return date
  10.         except ValueError:
  11.             print("请以YYYY-MM-DD格式输入日期")
  13. def test_get_date(monkeypatch, capfd):
  14.     inputs = [
  15.         "12/06/2023",
  16.         "12-06-2023",
  17.         "2023/06/12",
  18.         "2023/17/87",
  19.         "hello",
  20.         "2023-06-12",
  21.     ]
  22.     input_values = iter(inputs)
  23.     monkeypatch.setattr("builtins.input", lambda _: next(input_values))
  25.     # 无效输入测试
  26.     with pytest.raises(ValueError):
  27.         get_date("日期（YYYY-MM-DD）：")
  28.         captured = capfd.readouterr()
  29.         assert "请以YYYY-MM-DD格式输入日期" in captured.out
  31.     # 有效输入测试
  32.     assert get_date("日期（YYYY-MM-DD）：") == date(2023, 6, 12)
  33. capfd.readouterr()允许你捕获本应打印到控制台的输出。
  34. 如果你想了解更多，请参考[文档][1]。
  36. 希望这对你有帮助
  38. [1]: https://docs.pytest.org/en/6.2.x/capture.html
英文:

By adding raise, you re-raise the ValueError after printing the error msg and thus it crashes.

so if you want the program to repromt for the user to re-enter data remove the 'raise' statement in the get-date function.

Hope This Helps

Here is the whole code:

  1. import datetime
  2. import pytest
  4. def get_date(string):
  5.     while True:
  6.         try:
  7.             date_str = input(string)
  8.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  9.             return date
  10.         except ValueError:
  11.             print("Please enter a date in the YYYY-MM-DD format")
  13. def test_get_date(monkeypatch, capfd):
  14.     inputs = [
  15.         "12/06/2023",
  16.         "12-06-2023",
  17.         "2023/06/12",
  18.         "2023/17/87",
  19.         "hello",
  20.         "2023-06-12",
  21.     ]
  22.     input_values = iter(inputs)
  23.     monkeypatch.setattr("builtins.input", lambda _: next(input_values))
  25.     # invalid inputs test
  26.     with pytest.raises(ValueError):
  27.         get_date("Date (YYYY-MM-DD): ")
  28.         captured = capfd.readouterr()
  29.         assert "Please enter a date in the YYYY-MM-DD format" in captured.out
  31.     # valid input test
  32.     assert get_date("Date (YYYY-MM-DD): ") == date(2023, 6, 12)

capfd.readouterr() allows you to capture the output that would have been printed to the console.
if you wanna more about it doc

Hope This Is Helpful

答案2

得分: 1

以下是已翻译的代码部分：

  1. 这里有一种方法，它在 get_input 函数内封装了在输入错误的情况下重新提示用户的操作。
  3. def get_input(string):
  4.     date_str = input(string)
  5.     while True:
  6.         try:
  7.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  8.         except ValueError:
  9.             print("请以 YYYY-MM-DD 格式输入日期")
  10.             date_str = input(string)
  11.     return date
英文:

Here's an approach that encapsulates the re-prompting the user in case of an input error inside the get_input function.

  1. def get_input(string):
  2.     date_str = input(string)
  3.     while True:
  4.         try:
  5.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  6.         except ValueError:
  7.             print("Please enter a date in the YYYY-MM-DD format")
  8.             date_str = input(string)
  9.     return date

答案3

得分: 0

不需要将函数更改为布尔值。只需将日期字符串作为参数传递，并将用户输入移到单独的函数外部。

没有用户输入的get_date函数：

  1. def get_date(date_str):
  2.     try:
  3.         date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  4.         return date
  5.     except ValueError:
  6.         raise

测试：

  1. def test_get_date():
  2.     assert get_date("2023-06-12") == datetime.date(2023, 6, 12)
  4.     with pytest.raises(ValueError):
  5.         get_date("stuff")
  7.     with pytest.raises(ValueError):
  8.         get_date("2023/06/12")
  10.     with pytest.raises(ValueError):
  11.         get_date("2023/69/420")

在调用get_date之前，将用户输入添加回代码中，并将其作为date_str参数传递。

英文:

You don't need to change the function to a boolean. Instead just take the date string as an argument and move the user input outside to a separate function.

get_date function without user input:

  1. def get_date(date_str):
  2.     try:
  3.         date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  4.         return date
  5.     except ValueError:
  6.         raise

Testing:

  1. def test_get_date():
  2.     assert get_date("2023-06-12") == datetime.date(2023, 6, 12)
  4.     with pytest.raises(ValueError):
  5.         get_date("stuff")
  7.     with pytest.raises(ValueError):
  8.         get_date("2023/06/12")
  10.     with pytest.raises(ValueError):
  11.         get_date("2023/69/420")

Add the user input back into your code before you call get_date and hand it off as as the data_str argument.

答案4

得分: 0

你在原始代码中的思路是正确的 - 你只需要跳过对所有中间情况调用 get_date()，因为 get_date() 的执行将处理那些不良输入，然后提示下一个输入。

然后，在最后，我们可以断言输入列表已耗尽。

  1. #script.py
  2. import datetime
  4. def get_date(string):
  5.     # 使用循环而不是递归
  6.     while True:
  7.         try:
  8.             date_str = input(string)
  9.             date = datetime.datetime.strptime(date_str, "%Y-%m-%d").date()
  10.         except ValueError:
  11.             print("请以 YYYY-MM-DD 格式输入日期")
  13.     return date
  1. #test_script.py
  2. import pytest
  3. import datetime
  4. from script import get_date
  6. def test_get_date(monkeypatch):
  7.     inputs = [
  8.         "12/06/2023",
  9.         "12-06-2023",
  10.         "2023/06/12",
  11.         "2023/17/87",
  12.         "hello",
  13.         "2023-06-12",
  14.     ]
  15.     input_values = iter(inputs)
  16.     monkeypatch.setattr("builtins.input", lambda _: next(input_values))
  18.     # 测试所有其他输入是否都被处理，并接受最后一个输入
  19.     assert get_date("日期 (YYYY-MM-DD): ") == datetime.date(2023, 6, 12)
  21.     with pytest.raises(StopIteration):
  22.         _ = input("验证输入列表是否已耗尽")

如果输入列表未耗尽（在“接受”输入后还有值），则 Pytest 会失败，显示：

  1. FAILED test_script.py::test_get_date - Failed: DID NOT RAISE <class 'StopIteration'>
英文:

You have the correct idea in your original code - you just need to skip calling get_date for all the intermediate cases, because the execution of get_date() will handle those bad inputs, and then prompt for the next input.

Then at the end we can assert that the list of inputs was exhausted.

  1. #script.py
  2. import datetime
  4. def get_date(string):
  5.     # Use a loop, not recursion
  6.     while True:
  7.         try:
  8.             date_str = input(string)
  9.             date = datetime.datetime.strptime(date_str, &quot;%Y-%m-%d&quot;).date()
  10.         except ValueError:
  11.             print(&quot;Please enter a date in the YYYY-MM-DD format&quot;)
  12.     
  13.     return date
  1. #test_script.py
  2. import pytest
  3. import datetime
  4. from script import get_date
  6. def test_get_date(monkeypatch):
  7.     inputs = [
  8.         &quot;12/06/2023&quot;,
  9.         &quot;12-06-2023&quot;,
  10.         &quot;2023/06/12&quot;,
  11.         &quot;2023/17/87&quot;,
  12.         &quot;hello&quot;,
  13.         &quot;2023-06-12&quot;,
  14.     ]
  15.     input_values = iter(inputs)
  16.     monkeypatch.setattr(&quot;builtins.input&quot;, lambda _: next(input_values))
  18.     # Test that all other inputs were handled and we accept the last one
  19.     assert get_date(&quot;Date (YYYY-MM-DD): &quot;) == datetime.date(2023, 6, 12)
  21.     with pytest.raises(StopIteration):
  22.         _ = input(&quot;Verify inputs list is exhausted&quot;)

If the inputs list is not exhausted (there are values after an "accepted" input), then Pytest will fail with

  1. FAILED test_script.py::test_get_date - Failed: DID NOT RAISE &lt;class &#39;StopIteration&#39;&gt;

huangapple
  • 本文由 发表于 2023年6月14日 23:28:24
  • 转载请务必保留本文链接：https://go.coder-hub.com/76475217.html
  • pytest
  • python
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