20130314 (Thursday, 14 March 2013)

Still working on the “pip install lino” problem. Which takes so much time because I also work on the “better automated testing” problem.

  • Moved the uiless tutorial from lino to north where it is called The Polls tutorial. This caused yet another testing method run_bash_tests.
  • Trying the solution to move the media directory one level down into the lino package: hg mv media lino and one line in lino.ui.urls to change (todo: instructions for existing servers to move their symbolic link)
  • Deleted and re-uploaded once more the “official” PyPI releases (django-site and Nort 0.0.4, Lino 1.6.2).

How to include data files to a Python egg

I’d like that pip install lino also installs the files under /media so that Lino users can use it out of the box.

It wasn’t enough to just move the /media source directory to /lino/media. Why does it work for files like /lino/ui/linoweb.js? Because they are in a Python package, and because MANIFEST.in has an global-include instruction to include *.js files.

Should I have to turn it (and all the subdirectories!) into Python packages? One of them is e.g. lino/media/extjs/images/default/grid. That would be a few dozen of otherwise useless __init__.py files. No, there must be a better way.

The documentation section Accessing Data Files at Runtime says clearly what I’m doing wrong:

Typically, existing programs manipulate a package’s __file__ attribute in order to find the location of data files. However, this manipulation isn’t compatible with PEP 302-based import hooks, including importing from zip files and Python Eggs. It is strongly recommended that, if you are using data files, you should use the Resource Management API of pkg_resources to access them.

And the Accessing Package Resources link explains how to make it better.

Note that we are not yet trying to convert the linoweb.js file into a package resource because that’s an even more sophisticated case because Lino also maintains an automatically generated messages file linoweb.js.py to handle translation messages from this template.

In lino.ui.urls, instead of saying…


… I must say:

from pkg_resources import Requirement, resource_filename

This works on the development server of my machine where Lino is installed in editable mode using pip install -e. The resource_filename function correctly returns the name of that directory (I added a new INFO message to verify this):

INFO django.views.static serving /lino from t:\hgwork\lino\media

But will it work from a zipped egg? If resource_filename unzips these files to a new temporary directory each time, then we must expect problems. The development server would just need longer to start and fill the temporaty folder, but on a production server Lino creates a symbolic link to that directory, which is probably not what we want.

Maybe I should leave zip_safe to False because of this. Anyway it must remain False as long as the linoweb.js file is being read using __file__.

Of course I must also use either specify package_data or include_package_data in /lino/setup_info.py so that these files get distributed.

include_package_data : if set to True, this tells setuptools to automatically include any data files it finds inside your package directories, that are either under CVS or Subversion control, or which are specified by your MANIFEST.in file.

While working at these things I used the occasion to start splitting off the ExtJS UI into a separate project.

Once more I removed and replaced the Lino 1.6.2, North 0.0.4 and djangosite 0.0.4 releases at PyPI.

But when I try this on rose, I get:

Exception: /home/luc/luc/lib/python2.7/site-packages/media does not exist

The media directory with all these files is contained in the lino-1.6.2.tar.gz file, and the resource_filename function did return a string with a full path, but obviously there is no such directory …/python2.7/site-packages/media, and anyway it should be rather …/python2.7/site-packages/lino/media.

Maybe I must use package_data instead of include_package_data. Or maybe it’s enough to just move the media directory one level down to lino (again).

But stop here now! A customer is waiting for a Lino-Welfare release, and I decided to have the eggability problem wait now until the customer is satisfied. Lino cannot yet be used from a Python egg because of the above problems. I updated /tutorials/quickstart accordingly.

Preparing a release for Lino-Welfare

  • Fixed a bug “global name ‘PermissionDenied’ is not defined” which occured on demo4
  • Removed the css style x-grid3-cell-inner which defined a hard-coded height of 18px. So I restored ExtJS’s default behaviour. That’s needed for lino_welfare.modlib.jobs.models.NewJobsOverview.