RFC: Allow dot traversing to access nested dictionaries

[rochacbruno]

Lets take a settings.yaml

DEFAULT:
    REDIS:
        HOST: localhost
        PORT: 1234

To access the port you need to use one of:

settings.REDIS['PORT']        # may raise KeyError
settings['REDIS']['PORT']      # may raise KeyError
settings.REDIS.PORT           # possible because it is a Box(), but may raise AtributeError
settings.get('REDIS').PORT  # dict like get method
settings('REDIS')['PORT']      # the same as calling .get
settings.get('REDIS').get('PORT')  # may raise AttributeError

But what if you are not sure that the REDIS value is defined in settings.yaml and you don't wanna fail?

one way is relying on the .get default argument (dict like)

settings.get('REDIS', {}).get('PORT', 1234)

RFC: Allow traversing

settings('REDIS.PORT')   # would access the settings['REDIS']['PORT'] or raise KeyError.

settings('REDIS.PORT', 1234)   # if value cannot be accessed returns 1234 by default

The . should be parsed on LazySettings.get method and then perform the traversing.

Requirements

• Avoid regressions (keep backwards compatibility)
• Allow it to be disabled opt-out
• Ensure it does not include overhead by recursion and traversing
• Document it
• Write test cases
• Write examples/

[rochacbruno]

As dynaconf uses Box https://github.com/cdgriffith/Box this functionality is easy to implement, the major concern is about testing and performance

[allan-silva]

@rochacbruno, considering the given yaml, what should happen when the REDIS entry does not exist? Should the PORT be accessible?

[rochacbruno]

@allan-silva this feature has been implemented!

If the base REDIS does not exists then it raises keyerror.