Add shortcuts?

[merwok]

Would it be useful to add syntax shortcuts to make client code shorter?

store = configstore.Store()
store += configstore.EnvVarBackend()

if something:
    store += configstore.DotEnvBackend()

DEBUG = store['DEBUG']
DATABASES = {'default': dj_database_url.parse(store['DATABASE_URL'])}

[merwok]

@just1602 @JulienLabonte In general I prefer something explicit like store.add_backend(SomeBackend()) but I think += could be okay here; what do you think?

[just1602]

I'm not sure if I like that. I'm a big fan of clean method name like add_backend and keep operator for mathematical stuff. Like if we implement a class representing a matrix, it'd be nice to have the operator implementation, but for this case I don't know if I like it. But we could implement it since some people could use it and it'd be a good practice for the don't repeat yourself (DRY) principle. :)

[merwok]

I think it’s okay that classes that are not related to math concepts redefine operators to mean something meaningful for them (e.g. str + str, Path / str).

What I don’t like is that store += backend is equivalent to store = store + backend, and that does not make sense (compared to list1 += list2 <=> list1 = list1 + list2).

For the other shortcut, I don’t like that store['DEBUG'] looks like a direct access to local data but may actually involve I/O and AWS requests. (Same design rule that says a property should be a direct access, but a big computation or remote request needs a method call.) I suppose I would feel differently if instantiating the backend did all the I/O, and store[setting] only looked up in local data, but that’s not (except for DotEnvBackend!) the design we have now (and probably not one we want).

I do like add_backend, which is clear and unambiguous (compared to e.g. store.add). For get_setting, instead of dict item access maybe we could rename the method to get? (the similarity with dict.get is actually a pro, since we have equivalent signature and behaviour (default value or exception))

[merwok]

Other ideas for shortcuts:

store = configstore.Store(envvar=True)

if something:
    store.add_backend(dotenv='/path/to/.env')

# the dotenv backend will be added if envvar PROJECT_DOTENV_PATH exists
store = configstore.Store(envvar=True, dotenv='PROJECT_DOTENV_PATH')

# built-in backend
store.add_backend('docker')
# custom backend
store.add_backend(VaultBackend)

store = configstore.Store('envvar, dotenv:PROJECT_DOTENV_PATH')

[merwok]

See also https://getconf.readthedocs.io/en/latest/index.html#introduction for inspiration

getconf — getconf 1.9.0.dev0 documentation