Retrieving the full command line

[Tim Golden]

On 24/01/2013 16:53, Oscar Benjamin wrote:
>> Does it work if you use the -m option to run a module rather than a script?
> 
> Sorry that was written incorrectly. I meant to say: does it work when
> a module is directly on sys.path rather than as a submodule of a
> package? In this case __package__ is set to the empty string if run
> with -m or None if run with a direct path. So the check needs to be
> "__package__ is not None" rather than "bool(__package__)".

The answer is: it depends. Given the code I outlined earlier:

A package-based module run via -m (python -m package.module) works
as described (including the implicit __main__ module, my
primary use-case).

A module run from the filesystem (python c:\path\to\module.py) works
by dropping through through to the not is_package logic branch.

A module run via -m (python -m module) actually works by accident,
because it too drops through to the not is_package branch and is
rerun with its full filesystem path. This doesn't have the same
problems as running a package from the filesystem because relative
imports aren't an issue. I don't know if there are any other differences
between python -mmodule and python c:\path\to\module.py.

As you say, a more refined check could determine a blank __package__
as opposed to a None __package__. But this code (cherrypy) must also
cope with version of Python before 2.6 which didn't even have a
__package__ attribute, muddying the waters that little bit further.

TJG