config: allow libraries in default-settings

[alexfikl]

This should allow setting libraries in config.py using register_default_settings dynamically. Something like this should now work as expected

import pathlib

from papis.config import register_default_settings

basedir = pathlib.Path('/home/user/Documents')
register_default_settings({
    **{subdir.stem: {'dir': str(subdir)} for subdir in basedir.glob('[a-z]*/')},
	**{"settings": {"default-library": "lib1"}}
    })

xref: #851

[alexfikl]

@octvs In case you have the git version of papis available, it would be great if you get a chance to test this!

[octvs]

Just gave it a try with my original config files, however when I execute

$ papis -l INFO --pick-lib open

to see which libraries have been registered, I see the library defined as
default-library on [settings] section duplicated. Which justifies the
following block from your snippet:

if libname not in self:
    self.add_section(libname)

I will check the API doc to see whether I can refer back to already registered
libs on ConfigParser, which would let me include a similar check in a less
hacky way.

[alexfikl]

to see which libraries have been registered, I see the library defined as default-library on [settings] section duplicated.

@octvs Oops, nice catch! That should be fixed in the latest version.

I went with the following choice: if the library is defined in the static config file, it takes priority over a library with the same name defined in config.py using papis.config.register_default_settings.

[octvs]

Just gave it a try, it works as expected now.

if the library is defined in the static `config` file, it takes priority over a library with the same name defined in `config.py`

I wonder if this should be documented somewhere.

[alexfikl]

I wonder if this should be documented somewhere.

Yeah, it really should! I've opened an issue to improve the documentation for config.py, since at the moment it's pretty much non-existent.

Thanks for all the testing and help with this! In it goes! 🚀