Python flag/envvar to not put current directory on sys.path (but don't ignore PYTHONPATH)

[vstinner (Victor Stinner)]

@hroncok

Another use case for this flag. Our programs are installed into /usr/bin . We want them to not add /usr/bin to sys.path so we would add this flag to our shebang in Fedora. Otherwise having randomly named files in /usr/bin can interfere with Python programs, as described e.g. in bad magic number in ‘six’ · Issue #359 · benjaminp/six · GitHub

Oh right. I wrote gh-57684: Add -P cmdline option and PYTHONSAFEPATH env var by vstinner · Pull Request #31542 · python/cpython · GitHub to add -P option to Python, so you can add -P to the shebang to avoid the issue. Somewhere, it was proposed that setuptools should use such option since it generates scripts from entry points.