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[Python-ideas] Running scripts with relative imports directly, was: Re: proposal: "python -m foo"

Paul Sokolovsky pmiscml at gmail.com
Thu Aug 6 01:32:10 CEST 2015 
Hello,

On Wed, 5 Aug 2015 18:23:20 +0300
Paul Sokolovsky <pmiscml at gmail.com> wrote:

> I'm sorry for possibly hijacking this thread, but it touches very much
> issue I had on my mind for a while: being able to run modules inside
> package as normal scripts. As this thread already has few people
> knowledgeable of peculiarities of package imports, perhaps they can
> suggest something.
> 
> Scenario:
> 
> There's a directory ("pkg" (representing Python namespace package)),
> and inside it, there's bar.py of not relevant content and foo.py with
> "from . import bar". What I'd like to do is (while inside "pkg"
> directory):
> 
> python3 foo.py
> 
> Current behavior:
> 
> SystemError: Parent module '' not loaded, cannot perform relative
> import
> 
> Expected behavior:
> 
> "from . import bar" in foo.py is successful.


Perhaps I was asking something dumb, or everyone just takes for granted
that nowadays Python code can't be developed comfortably without IDE,
or 2+ console windows open, or something. But I find it quite a sign of
problem, because if one accepts that one can't just run a script right
away, but needs to do extra steps, then well, that enterprisey niche is
pretty crowded and there're more choices how to make it more
complicated.

So, I did my homework (beyond just googling, which unfortunately didn't
turn up much), and being able to do it with a simple "loader" and
"single command line switch" like:

python3 -mruninpkg script.py arg1 arg2 arg3

restored my piece of mind.

The script is here: https://github.com/pfalcon/py-runinpkg . Hope
someone else will find its existence insightful, or maybe someone will
suggest how to make it better (I see the bottleneck in that it's not
possible to make mod.__name__ an empty string, and that's what would
be needed here to avoid double-import problem). 

I actually did another googling session, and there's definitely a niche
for such solution, like this 10-years old article shows:

http://code.activestate.com/recipes/307772-executing-modules-inside-packages-with-m/

If only there were good, widely known inventory of them for different
usecases...



-- 
Best regards,
 Paul                          mailto:pmiscml at gmail.com
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