Curious configuration file

[pypingou]

Hi,

I was just curious if there is any special reason you went with a yaml configuration file instead of using the approach flasks support: http://flask.pocoo.org/docs/0.10/config/#configuring-from-files

Thanks

[buhman]

instead of using the approach flasks support

pb uses app.config.from_mapping, which is new in 1.0--the main point of from_mapping is to help use-cases just like this. So I'm not sure what you mean by "support".

any special reason

Yes. pyfile syntax doesn't support nested objects. A good example of how pb exploited this was back when we used MySQL, the configuration looked like this.

Notice that the dictionary keys within MYSQL exactly match they keyword arguments used by mysql.connector.connect, which results in fun sugar like this.

The other cool thing about that is you're able to pass arbitrary keyword arguments (other than the required/mandatory/documented arguments) to connect() if you need to without pb having explicit logic for said arguments.

This is still used with Mongo as well.

[buhman]

The alternative is less pretty; something like:

FOO_SPAM=heh
FOO_EGGS=wut

foo(spam=config['FOO_SPAM'], eggs=config['FOO_EGGS'])

yaml

Standardized, easy to read/write, and extremely flexible.

[pypingou]

the pyfile syntax allows you to use plain python dictionary, which will end up to be the same thing as your yaml structure.

It also gives you the benefit of actually embedding python code in your configuration file (for example see how to configure a session time-out, which directly calls datetime.timedelta: http://flask.pocoo.org/docs/0.10/api/#flask.session.permanent)

Anyway, I was merely curious :)

[buhman]

actually embedding python code in your configuration file

I consider this to be a solid anti-feature. I'd completely forgotten that from_pyfile actually does exec().