:date: 2018-05-06

===================
Sunday, May 6, 2018
===================

I fiddled around on :ref:`travis` and readthedocs with pip, the
package names of dependencies, especially appy.

We must differentiate between the *dependency* name and the *package*
name.  A dependency usually has the same name as the package it
installs.  But not always.

In the :xfile:`requirements.txt` file of :ref:`book` I had until now::

  -e git+https://github.com/lino-framework/appypod.git#egg=appy

Maybe that line should rather be::

  git+https://github.com/lino-framework/appypod.git#egg=appypod

Some quotations from the pip docs at `pip.pypa.io
<https://pip.pypa.io/en/stable/user_guide/#requirements-files>`__:


- Requirements files are used to override a dependency with a local
  patch that lives in version control. For example, suppose a
  dependency, SomeDependency from PyPI has a bug, and you can't wait
  for an upstream fix. You could clone/copy the src, make the fix, and
  place it in VCS with the tag sometag. You'd reference it in your
  requirements file with a line like so::

    git+https://myvcs.com/some_dependency@sometag#egg=SomeDependency
    
- If *SomeDependency* was previously a top-level requirement in your
  requirements file, then **replace** that line with the new line. If
  *SomeDependency* is a sub-dependency, then **add** the new line.

- It's important to be clear that pip determines package dependencies
  using install_requires metadata, not by discovering requirements.txt
  files embedded in projects.

  
I tried the following in my local py3 environment::

    $ pip freeze | grep appy
    -e git+git@github.com:lino-framework/appypod.git@acefc6634f498a7f64c12ae9794f572357566811#egg=appy
    appypod==0.1
  
Not sure why I have two lines there.  And more surprisingly, I can
uninstall them both with a single command::

    $ pip uninstall appy
    Uninstalling appy-0.1:
      Would remove:
        /media/dell1tb/virtualenvs/py3/lib/python3.5/site-packages/appy.egg-link
    Proceed (y/n)? y
      Successfully uninstalled appy-0.1

    $ pip freeze | grep appy

    $ go appypod

    $ pip install -e .
    Obtaining file:///media/dell1tb/work/appypod
    Requirement already satisfied: future in /media/dell1tb/virtualenvs/py3/lib/python3.5/site-packages (from appypod==0.1) (0.16.0)
    lino-welfare 17.10.0 requires suds, which is not installed.
    lino-xl 17.10.0 requires appy, which is not installed.
    Installing collected packages: appypod
      Running setup.py develop for appypod
    Successfully installed appypod

    $ pip freeze | grep appy
    appy==0.1
    -e git+git@github.com:lino-framework/appypod.git@acefc6634f498a7f64c12ae9794f572357566811#egg=appypod

Now the dependency name is "appypod" and not "appy"::
    
    $ pip uninstall appy
    Not uninstalling appy at /media/dell1tb/work/appypod, outside environment /media/dell1tb/virtualenvs/py3
    Can't uninstall 'appy'. No files were found to uninstall.
    
    $ pip uninstall appypod
    Uninstalling appypod-0.1:
      Would remove:
        /media/dell1tb/virtualenvs/py3/lib/python3.5/site-packages/appypod.egg-link
    Proceed (y/n)? y
      Successfully uninstalled appypod-0.1


Oops, I learned only today that there is already a dependency named
*appypod* on PyPI::

    $ pip install appypod
    Collecting appypod
      Downloading https://files.pythonhosted.org/packages/0d/52/0bd6ed03c5e2795ef648312e055db65496274833e9912ed0dc1ea25bad8a/appypod-0.9.6.tar.gz (121kB)
        100% |████████████████████████████████| 122kB 2.5MB/s 
    Building wheels for collected packages: appypod
      Running setup.py bdist_wheel for appypod ... done
      Stored in directory: /home/luc/.cache/pip/wheels/24/29/fc/96dbd1fa4d9fec170e4ef29f3f6701a8e3720e7b8f1ed1768e
    Successfully built appypod
    lino-welfare 17.10.0 requires suds, which is not installed.
    lino-xl 17.10.0 requires appy, which is not installed.
    Installing collected packages: appypod
    Successfully installed appypod-0.9.6



TIL what the ``-e`` options (`editable
<https://pip.pypa.io/en/stable/reference/pip_install/#editable-installs>`__
install using `development mode
<https://setuptools.readthedocs.io/en/latest/setuptools.html#development-mode>`__)
at the beginning of each line in our :xfile:`requirements.txt` files
are good for: without them the template files in :xfile:`config`
directories are missing.  Most projects with Lino plugins have some
template file.  Also Appy has at least one::

    FileNotFoundError: [Errno 2] No such file or directory: '/home/travis/virtualenv/python3.6.3/lib/python3.6/site-packages/appy/pod/content.xmlt'

Projects that need the ``-e`` option, actually have a problem when
installed by simply using ``pip install``.  Actually all template
files should be declared somewhere in the :xfile:`setup.py` or the
:xfile:`MANIFEST.in` file

This should actually not be a problem if we declare the package data
correctly.  For example this error message::

    IOError: [Errno 2] No such file or directory: '/home/travis/virtualenv/python2.7.14/lib/python2.7/site-packages/etgen/sepa/XSD/pain.001.001.02.xsd'

Should get fixed by saying::
    
    SETUP_INFO.update(include_package_data=True, zip_safe=False)
    SETUP_INFO.update(package_data={
        'etgen.sepa': ['XSD/pain.001.001.02.xsd'],
    })