[issue21202] Naming a file` io.py` causes cryptic error message
New submission from Madison May: Naming a file `io.py` in the root directory of a project causes the following error on 2.7: AttributeError: 'module' object has no attribute 'BufferedIOBase' Similar issues arise on 3.x., although the error message is a bit more useful: Fatal Python error: Py_Initialize: can't initialize sys standard streams AttributeError: 'module' object has no attribute 'OpenWrapper' At the very least we should ensure that the error message is a bit more straightforward and clear, as I imagine its not all that uncommon to cause this kind of conflict. ---------- assignee: docs@python components: Documentation, IO messages: 215940 nosy: docs@python, madison.may priority: normal severity: normal status: open title: Naming a file` io.py` causes cryptic error message versions: Python 2.7 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Madison May <madison.may@students.olin.edu>: ---------- versions: +Python 3.5 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Ned Deily added the comment: Using a local module name that shadows one in the standard library is a very common "import trap". See, for example, https://ncoghlan_devs-python-notes.readthedocs.org/en/latest/python_concepts.... I did a quick search through the documentation and didn't find an explicit reference to the general topic. If it isn't already, it probably should be mentioned in the tutorial and the FAQ. I don't think that 'io' should be special-cased. ---------- components: -IO nosy: +ned.deily _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Brett Cannon added the comment: While mentioning something in the FAQ and/or tutorial is fine, I wouldn't want to change Python's message too much to deal with this unless it was extremely fast (e.g. we pre-generated a set and check that on ImportError and then modified the message only in those instances). ---------- nosy: +brett.cannon _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Ezio Melotti <ezio.melotti@gmail.com>: ---------- nosy: +ezio.melotti, ncoghlan type: -> behavior _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Madison May added the comment: I definitely agree that io shouldn't be special cased, as it's more about the name shadowing issue that this specific example. A simple docs addition would make me happy, to be honest. ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Florent Xicluna <florent.xicluna@gmail.com>: ---------- nosy: +flox _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Martin v. Löwis added the comment: I think the AttributeError message should improve, and special-case certain common types, in particular modules. E.g. it could read AttributeError: module 'io' has no attribute 'BufferedIOBase' or even AttributeError: <module 'io' from 'C:\\Program Files\\Python34\\lib\\io.py'> has no attribute 'BufferedIOBase' IIUC, the first version would already have helped the OP, and the second version would have been dead-clear (except that it is a little verbose). ---------- nosy: +loewis _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Christian Theune <ct@gocept.com>: ---------- hgrepos: +238 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Christian Theune added the comment: I managed to create a patch that relies (in hopefully reasonably safe manner) on embedding an object repr for identification in this and similar cases. This is basically what implements what Martin suggested. Caveat emptor: my C knowledge is only good enough to be dangerous. Thomas Wouters and RDM helped me through it. I haven't adapted the tests yet (lots of failures due to the output change) but I managed them to stop crashing. The 'repr.py' in the root is my current testbed to see what's going on. ---------- nosy: +ctheune, r.david.murray, twouters _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Christian Theune <ct@gocept.com>: ---------- keywords: +patch Added file: http://bugs.python.org/file34937/4ae151db1bd9.diff _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Jesús Cea Avión <jcea@jcea.es>: ---------- nosy: +jcea _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
Changes by Ezio Melotti <ezio.melotti@gmail.com>: ---------- stage: -> test needed _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21202> _______________________________________
STINNER Victor <vstinner@redhat.com> added the comment: No activity for 5 years, I close the issue. ---------- nosy: +vstinner resolution: -> out of date stage: test needed -> resolved status: open -> closed _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue21202> _______________________________________
participants (9)
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Brett Cannon -
Christian Theune
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Ezio Melotti
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Florent Xicluna
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Jesús Cea Avión
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Madison May
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Martin v. Löwis
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Ned Deily
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STINNER Victor