Dynamic settings: there is no way to return None, False, 0, empty string

[unknownlighter]

if self._dynamic_reader:
    dynamic_result = self._dynamic_reader.get(attr)
    if dynamic_result:
        self._dict[attr] = dynamic_result
        result = dynamic_result

This code does not allow to return from dynamic_reader value that doesn't meet the condition if self._dynamic_reader: such as None, False, 0, ''

[unknownlighter]

I suggest that _dynamic_reader should raise AttributeError if attr not found. Then

if self._dynamic_reader:
    try:
    	dynamic_result = self._dynamic_reader.get(attr)
    except AttributeError:
    	pass
    else:
        self._dict[attr] = dynamic_result
        result = dynamic_result

[drgarcia1986]

make sense, how do you think about handle this behavior (raise AttributeError) on dynamic_settings backends (e.g. Redis)?

[drgarcia1986]

to begin we can check if result is diferent of None and not a "non zero" value, e.g.:

if self._dynamic_reader:
    dynamic_result = self._dynamic_reader.get(attr)
    if dynamic_result is not None:  # <---
        self._dict[attr] = dynamic_result
        result = dynamic_result

This change fix issues with 0, '' and False, what do you think @unknownlighter ?

[unknownlighter]

python redis client has a different behavior for cases when key was not found and when key has None value:

>>> import redis
>>> r = redis.StrictRedis()
>>> r.get('foo')
>>> r.set('foo', None)
True
>>> r.get('foo')
b'None'

so we can raise AttributeError when redis returned None and return None when redis returned b'None'

[unknownlighter]

Anyway, check for None value (if dynamic_result is not None:) much better than current behavior

[drgarcia1986]

Great, I'll work on it!

[drgarcia1986]

Thank you @unknownlighter for your feedback, I'll release a hotfix soon.

[unknownlighter]

Great. Thank you @drgarcia1986 for fast response and fix