[Python-Dev] PEP 379 Python launcher for Windows (original) (raw)

[Python-Dev] PEP 379 Python launcher for Windows - behaviour for #!/usr/bin/env python line is wrong

Paul Moore p.f.moore at gmail.com
Sat May 4 17:15:54 CEST 2013

On 4 May 2013 15:20, Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:

Paul Moore <p.f.moore gmail.com> writes:

> This will mean that scripts written with #!/usr/bin/env python will > behave the same on Unix and Windows in the presence of activated > virtualenvs. Overall I think it's the right result. There's one other compatibility clarification: at the moment, as allowed by the PEP, you can have launcher flags in a line that starts with #!/usr/bin/env python, for example #!/usr/bin/env python3.2-32 -u In such a case the launcher would use the 3.2-32 suffix to indicate that 32-bit Python 3.2 is wanted, and pass the -u to the launched executable. I assume that this behaviour should continue, and the Posix-compatible behaviour being proposed should only apply for lines that contain "#!/usr/bin/env python" followed by whitespace.

That sounds reasonable - I've never used the ability to add flags, but I agree that as there's no equivalent in POSIX, there's no reason to change the current behaviour in that case.

Also, since we're making a backwards incompatible change, do people feel that it needs to be switched on only in the presence of e.g. an environment variable such as PYLAUNCHSEARCHPATH, or should we just change the default behaviour now and risk breaking user scripts which may rely on the current behaviour?

Personally, I'd say make it unconditional - the current behaviour is unlikely to ever be what people actually want.

But if the consensus is to make it conditional, could we have a flag in py.ini rather than an environment variable? That would be more consistent with normal Windows practice.

Paul.

PS Vinay - from this post, I assume you're already looking at this code? I was considering trying to put together a patch, but I don't want to duplicate effort if you're working on it. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20130504/1192c78f/attachment.html>

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