New submission from Brian Skinn <bsk...@alum.mit.edu>:
In [this project](https://github.com/bskinn/stdio-mgr) of mine, I have a tox matrix set up with Pythons from 3.3. to 3.8. I have pytest set up to run doctest on my [`README.rst`](https://github.com/bskinn/stdio-mgr/blob/6444cce8e5866e2d519c1c0630551d8867f30c9a/README.rst). For Pythons 3.4 to 3.7 (3.4.10, 3.5.7, 3.6.8, 3.7.2), the following doctest example passes: ``` >>> import warnings >>> with stdio_mgr() as (in_, out_, err_): ... warnings.warn("'foo' has no 'bar'") ... err_cap = err_.getvalue() >>> err_cap "...UserWarning: 'foo' has no 'bar'\n..." ``` Under Python 3.8.0a3, though, it fails (actual local paths elided): ``` $ tox -re py38-attrs_latest .package recreate: .../.tox/.package .package installdeps: wheel, setuptools, attrs>=17.1 py38-attrs_latest recreate: .../.tox/py38-attrs_latest py38-attrs_latest installdeps: attrs, pytest py38-attrs_latest inst: .../.tox/.tmp/package/1/stdio-mgr-1.0.2.dev1.tar.gz py38-attrs_latest installed: atomicwrites==1.3.0,attrs==19.1.0,more-itertools==7.0.0,pluggy==0.9.0,py==1.8.0,pytest==4.4.1,six==1.12.0,stdio-mgr==1.0.2.dev1 py38-attrs_latest run-test-pre: PYTHONHASHSEED='2720295779' py38-attrs_latest run-test: commands[0] | pytest =============================================================================================== test session starts ================================================================================================ platform linux -- Python 3.8.0a3, pytest-4.4.1, py-1.8.0, pluggy-0.9.0 cachedir: .tox/py38-attrs_latest/.pytest_cache rootdir: ..., inifile: tox.ini collected 6 items README.rst F [ 16%] tests/test_stdiomgr_base.py ..... [100%] ===================================================================================================== FAILURES ===================================================================================================== _______________________________________________________________________________________________ [doctest] README.rst _______________________________________________________________________________________________ 077 078 **Mock** ``stderr``\ **:** 079 080 .. code :: 081 082 >>> import warnings 083 >>> with stdio_mgr() as (in_, out_, err_): 084 ... warnings.warn("'foo' has no 'bar'") 085 ... err_cap = err_.getvalue() 086 >>> err_cap Expected: "...UserWarning: 'foo' has no 'bar'\n..." Got: '<doctest README.rst[4]>:2: UserWarning: \'foo\' has no \'bar\'\n warnings.warn("\'foo\' has no \'bar\'")\n' .../README.rst:86: DocTestFailure ======================================================================================== 1 failed, 5 passed in 0.06 seconds ======================================================================================== ERROR: InvocationError for command .../.tox/py38-attrs_latest/bin/pytest (exited with code 1) _____________________________________________________________________________________________________ summary ______________________________________________________________________________________________________ ERROR: py38-attrs_latest: commands failed ``` If I change the doctest in README to the following, where the expected output is surrounded by single-quotes instead of double-quotes, and the internal single quotes are escaped, it passes fine in 3.8.0a3: ``` >>> import warnings >>> with stdio_mgr() as (in_, out_, err_): ... warnings.warn("'foo' has no 'bar'") ... err_cap = err_.getvalue() >>> err_cap '...UserWarning: \'foo\' has no \'bar\'\n...' ``` But, naturally, it fails in 3.7 and below. It *looks* like this is probably a glitch somewhere in 3.8.0a3, where this string containing single quotes is rendered (at the REPL?) using enclosing single quotes and escaped internal single quotes, rather than enclosing double-quotes and non-escaped internal single-quotes? ---------- components: Library (Lib) messages: 340637 nosy: bskinn priority: normal severity: normal status: open title: Change (regression?) in v3.8.0a3 doctest output after capturing the stderr output from a raised warning type: behavior versions: Python 3.8 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36695> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
