New submission from Erik Carstensen <mandolae...@gmail.com>:
I can find partial information on how Python treats __main__.py here: https://docs.python.org/3/library/__main__.html However, it is not documented how python handles __main__.py when passing the Python package to the interpreter without -m. If I have a program defined by /tmp/foo/bar.py and a file /tmp/foo/__main__.py, and I run python /tmp/foo ... then Python will run __main__.py, with /tmp/foo prepended to sys.path. I find this behaviour unfortunate; to me it would make more sense to prepend /tmp to sys.path, because then "python /tmp/foo" would be equivalent to "PYTHONPATH=/tmp python -m foo". With the current behaviour, if __main__.py wants to import bar.py, then it must write 'import bar' or 'import foo.bar' depending on whether the interpreter was invoked with -m. Unfortunately, by Hyrum's Law, you can find people describing and encouraging reliance upon the current undocumented behaviour, e.g.: https://www.geeksforgeeks.org/usage-of-__main__-py-in-python/ so perhaps the behaviour can't be changed that easily. Therefore, my request is to document how it works. ---------- assignee: docs@python components: Documentation messages: 396865 nosy: docs@python, mandolaerik priority: normal severity: normal status: open title: incomplete documentation of __main__.py type: behavior versions: Python 3.10, Python 3.11, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44552> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
