On Oct 12, 3:34 pm, "Gabriel Genellina" <gagsl-...@yahoo.com.ar> wrote: > En Mon, 12 Oct 2009 15:24:34 -0300, Buck <workithar...@gmail.com> escribió: > > > On Oct 10, 9:44 am, "Gabriel Genellina" <gagsl-...@yahoo.com.ar> > > wrote: > >> The good thing is that, if the backend package is properly installed > >> somewhere in the Python path ... it still works with no modifications. > > > I'd like to get to zero-installation if possible. It's easy with > > simple python scripts, why not packages too? I know the technical > > reasons, but I haven't heard any practical reasons. > > > If the reasons are purely technical, it smells like a PEP to me. > > That's what I meant to say. It IS a zero-installation schema, and it also > works if you properly install the package. Quoting Steven D'Aprano > (changing names slightly): > > """You would benefit greatly from separating the interface from > the backend. You should arrange matters so that the users see something > like this: > > project/ > +-- animal > +-- mammal > +-- reptile > +-- somepackagename/ > +-- __init__.py > +-- animals.py > +-- mammals/ > +-- __init__.py > +-- horse.py > +-- otter.py > +-- reptiles/ > +-- __init__.py > +-- gator.py > +-- newt.py > +-- misc/ > +-- __init__.py > +-- lungs.py > +-- swimming.py > > where the front end is made up of three scripts "animal", "mammal" and > "reptile", and the entire backend is in a package.""" [ignore the rest] > > By example, the `animal` script would contain: > > from somepackagename import animals > animals.main() > > or perhaps something more elaborate, but in any case, the script imports > whatever it needs from the `somepackagename` package. > > The above script can be run: > > a) directly from the `project` directory; this could be a checked out copy > from svn, or a tar file extracted in /tmp, or whatever. No need to install > anything, it just works. > > b) alternatively, you may install somepackagename into site-packages (or > the user site directory, or any other location along the Python path), and > copy the scripts into /usr/bin (or any other location along the system > PATH), and it still works. > > The key is to put all the core functionality into a package, and place the > package where Python can find it. Also, it's a good idea to use relative > imports from inside the package. There is no need to juggle with sys.path > nor even set PYTHONPATH nor import __main__ nor play any strange games; it > Just Works (tm). > > -- > Gabriel Genellina
Hi Gabriel. This is very thoughtful. Thanks. As in the OP, when I have 50 different runnable scripts, it become necessary to arrange them in directories. How would you do that in your scheme? Currently it looks like they're required to live directly above the package containing their code. --Buck -- http://mail.python.org/mailman/listinfo/python-list
