From 97b9c1096feff77a564787ef520cc7d4e1d1c45f Mon Sep 17 00:00:00 2001 From: CAM Gerlach Date: Thu, 19 May 2022 08:59:07 -0600 Subject: gh-92417: Update docs and examples of doctest.IGNORE_EXCEPTION_DETAIL for Py>=3 (GH-92502) --- Doc/library/doctest.rst | 48 +++++++++++++++++++++--------------------------- 1 file changed, 21 insertions(+), 27 deletions(-) diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst index be5651d..2d50a49 100644 --- a/Doc/library/doctest.rst +++ b/Doc/library/doctest.rst @@ -563,41 +563,35 @@ doctest decides whether actual output matches an example's expected output: .. data:: IGNORE_EXCEPTION_DETAIL - When specified, an example that expects an exception passes if an exception of - the expected type is raised, even if the exception detail does not match. For - example, an example expecting ``ValueError: 42`` will pass if the actual - exception raised is ``ValueError: 3*14``, but will fail, e.g., if - :exc:`TypeError` is raised. + When specified, doctests expecting exceptions pass so long as an exception + of the expected type is raised, even if the details + (message and fully-qualified exception name) don't match. - It will also ignore the module name used in Python 3 doctest reports. Hence - both of these variations will work with the flag specified, regardless of - whether the test is run under Python 2.7 or Python 3.2 (or later versions):: + For example, an example expecting ``ValueError: 42`` will pass if the actual + exception raised is ``ValueError: 3*14``, but will fail if, say, a + :exc:`TypeError` is raised instead. + It will also ignore any fully-qualified name included before the + exception class, which can vary between implementations and versions + of Python and the code/libraries in use. + Hence, all three of these variations will work with the flag specified: - >>> raise CustomError('message') + .. code-block:: pycon + + >>> raise Exception('message') Traceback (most recent call last): - CustomError: message + Exception: message - >>> raise CustomError('message') + >>> raise Exception('message') Traceback (most recent call last): - my_module.CustomError: message + builtins.Exception: message - Note that :const:`ELLIPSIS` can also be used to ignore the - details of the exception message, but such a test may still fail based - on whether or not the module details are printed as part of the - exception name. Using :const:`IGNORE_EXCEPTION_DETAIL` and the details - from Python 2.3 is also the only clear way to write a doctest that doesn't - care about the exception detail yet continues to pass under Python 2.3 or - earlier (those releases do not support :ref:`doctest directives - ` and ignore them as irrelevant comments). For example:: - - >>> (1, 2)[3] = 'moo' + >>> raise Exception('message') Traceback (most recent call last): - File "", line 1, in - TypeError: object doesn't support item assignment + __main__.Exception: message - passes under Python 2.3 and later Python versions with the flag specified, - even though the detail - changed in Python 2.4 to say "does not" instead of "doesn't". + Note that :const:`ELLIPSIS` can also be used to ignore the + details of the exception message, but such a test may still fail based + on whether the module name is present or matches exactly. .. versionchanged:: 3.2 :const:`IGNORE_EXCEPTION_DETAIL` now also ignores any information relating -- cgit v0.12