self.assertRaisesRegex无法工作，“在处理上述异常期间，发生了另一个异常”。

Question

我的python单元测试调用

self.assertRaisesRegex(Exception, "Missing price data for hids: {123}", self.idc_service.load_prices, date(2021, 2, 22), date(2021, 2, 23), [123])

这将导致错误：

Failure
Exception: Missing price data for hids: {123}

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 59, in testPartExecutor
    yield
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 615, in run
    testMethod()
  File "C:\Users\Alin\Desktop\code\pyApps\pyApps\tests\services\TestIdcDataService.py", line 32, in test_missing_hid_prices
    self.assertRaisesRegex(Exception, "Missing price data for hids: {123}", self.idc_service.load_prices, date(2021, 2, 22), date(2021, 2, 23), hids)
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 1285, in assertRaisesRegex
    return context.handle('assertRaisesRegex', args, kwargs)
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 178, in handle
    callable_obj(*args, **kwargs)
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 217, in __exit__
    expected_regex.pattern, str(exc_value)))
  File "C:\ProgramData\Miniconda3\lib\unittest\case.py", line 135, in _raiseFailure
    raise self.test_case.failureException(msg)
AssertionError: "Missing price data for hids: {123}" does not match "Missing price data for hids: {123}"

断言错误令人困惑，因为这两个字符串完全匹配。消息“在处理上述异常期间发生了另一个异常”是否发生了什么情况？

Answer 1

{}对regexes有特殊的意义，您需要逃离它们。

self.assertRaisesRegex(Exception, r"Missing price data for hids: \{123\}", self.idc_service.load_prices, date(2021, 2, 22), date(2021, 2, 23), [123])