o3bvv / candv Goto Github PK

Make constant's reference to own container public instead of protected.

Assume you have the following package structure:

.
└── x
    ├── __init__.py
    └── y
        ├── __init__.py
        └── constants.py

where x.y.constants.py contains the following:

# -*- coding: utf-8 -*-

from candv import Constants, SimpleConstant


class FOO_TYPES(Constants):
    PRIMARY = SimpleConstant()
    SECONDARY = SimpleConstant()

If x is in Python's path, and you import constants from x.y and simply from y, then their module will differ and comparison of constants will fail:

>>> import sys
>>> sys.path.insert(0, './x')
>>> from x.y.constants import FOO_TYPES as X_TYPES
>>> from y.constants import FOO_TYPES as Y_TYPES
>>> X_TYPES.__module__
'x.y.constants'
>>> Y_TYPES.__module__
'y.constants'
>>> X_TYPES.PRIMARY
<constant 'FOO_TYPES.PRIMARY'>
>>> Y_TYPES.PRIMARY
<constant 'FOO_TYPES.PRIMARY'>
>>> X_TYPES.PRIMARY == Y_TYPES.PRIMARY
False

Solution: constants base must implement own __hash__ and __eq__ magic methods, whose result will be based on full name of constant.

Add ability to get:

• name of container (alias for __name__)
• full name of container
• __repr__ of a container
• __repr__ of a group
• full name of a constant, which will include name of container

Provide ability to set dynamic values for constants using some storage (e.g. integrate with Redis, django-constance or whatsoever).

Add support of default values for such methods as get_by_name, get_by_value, etc.

Add ability to specify class of constants via dynamic mixin, e.g. this:

class FOO(Constants):
    constant_class = FOO_CONSTANT

    ONE = FOO_CONSTANT()
    TWO = FOO_CONSTANT()

with decorator will look like:

class FOO(with_constant_class(FOO_CONSTANT), Constants):    
    ONE = FOO_CONSTANT()
    TWO = FOO_CONSTANT()

Constants which are not instances of container's constant_class are not initialized. E.g.

>>> from candv import Values, SimpleConstant
>>> class FOO(Values):
...     BAR = SimpleConstant()
...     
... 
>>> FOO.BAR

>>> FOO.BAR.name
>>> repr(FOO.BAR)
''

Despite FOO.BAR is invalid, it still needs to be initialized.