Commit 4ef55a03 authored by Pietro Saccardi's avatar Pietro Saccardi
Browse files

Improvements to DotDict and settings. 

* DotDicts are lazily replaced over dicts when __getattr__ is called.
* DotDicts hierarchy is created lazily, when the value is set, the
  DotDict is stored in the parent object
* Added get method that can sanitize and cast the value
parent 641a07f4

misc/dotdict.py

+70 −14
Original line number Diff line number Diff line 
# https://stackoverflow.com/a/13520518/1749822

class DotDict(dict):

    __delattr__ = dict.__delitem__

class DotDict:

    _PASSTHROUGH_MEMBERS = ('_d', '_parent_and_key')



    def __setattr__(self, key, value):

        if isinstance(value, dict):

            value = DotDict(value)

        self[key] = value

    def __delattr__(self, item):

        if item in self._d:

            del self._d[item]



    def __getattr__(self, item):

        return self.get(item, None)

        if item in DotDict._PASSTHROUGH_MEMBERS:

            return super(DotDict, self).__getattr__(item)

        if item in self._d:

            retval = self._d[item]

            if isinstance(retval, dict):

                retval = DotDict(retval)

                self._d[item] = retval

            return retval

        else:

            return DotDict({}, (self, item))



    def __setattr__(self, key, value):

        if key in DotDict._PASSTHROUGH_MEMBERS:

            super(DotDict, self).__setattr__(key, value)

            return

        self._d[key] = value

        if self._parent_and_key is not None:

            setattr(*self._parent_and_key, self._d)

            self._parent_and_key = None



    def __contains__(self, item):

        return item in self._d



    def __iter__(self):

        return iter(self._d)



    def items(self):

        for k in self:

            yield k, getattr(self, k)



    def values(self):

        for k in self:

            yield getattr(self, k)



    def get(self, key, default=None, cast_to_type=None, ge=None, le=None, sanitizer=None):

        if key in self:

            retval = getattr(self, key)

            if cast_to_type is not None:

                # noinspection PyBroadException

                try:

                    retval = cast_to_type(retval)

                except:

                    retval = default

        else:

            retval = default

        if sanitizer is not None:

            retval = sanitizer(retval)

        if retval is not None and ge is not None:

            retval = max(retval, ge)

        if retval is not None and le is not None:

            retval = min(retval, le)

        return retval



    def __init__(self, d, parent_and_key=None):

        self._d = d

        self._parent_and_key = parent_and_key



    def __init__(self, dct):

        super(DotDict, self).__init__(dct)

        for key, value in self.items():

            if isinstance(value, dict):

                self[key] = DotDict(value)

    def _downcast_and_get_d(self):

        for k, v in self._d.items():

            if isinstance(v, DotDict):

                self._d[k] = v._downcast_and_get_d()

        return self._d



    def to_dict_tree(self):

        return dict({k: v.to_dict_tree() if isinstance(v, DotDict) else v for k, v in self.items()})
 
    def get_storage(self, downcast=True):

        if downcast:

            self._downcast_and_get_d()

        return self._d

misc/settings.py

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ def save_settings(path, log=None): 
    path = os.path.abspath(path)

    try:

        with open(path, 'w') as fp:

            json.dump(SETTINGS.to_dict_tree(), fp, cls=ExtendedJSONCodec, indent=2)

            json.dump(SETTINGS.get_storage(downcast=True), fp, cls=ExtendedJSONCodec, indent=2)

    except OSError:  # pragma: no cover

        if log:

            log.exception('Could not write to settings file %s.', path)

misc/tests.py

+23 −1
Original line number Diff line number Diff line
@@ -95,9 +95,31 @@ class TestDotDict(unittest.TestCase): 
        self.assertIsNotNone(d.b)

        self.assertIsNotNone(d.b.c)

        self.assertIsInstance(d.b.c, DotDict)

        d = d.to_dict_tree()

        d = d.get_storage()

        self.assertEqual(d, {'a': {}, 'b': {'c': {}}})



    def test_lazy_alloc(self):

        d = DotDict({})

        self.assertIsNone(d.something.get('a'))

        self.assertNotIn('something', d)

        d.something.a = 55

        self.assertIn('something', d)

        self.assertIn('a', d.something)

        self.assertEqual(d.something.a, 55)



    def test_get(self):

        d = DotDict({'a': 55})

        self.assertIsNone(d.get('b'))

        self.assertEqual(d.get('a'), 55)

        self.assertEqual(d.get('b', default=42), 42)

        d.c = '55'

        self.assertEqual(d.get('c', cast_to_type=int), 55)

        d.c = 'string'

        self.assertEqual(d.get('c', cast_to_type=int, default=32), 32)

        self.assertEqual(d.get('a', ge=56), 56)

        self.assertEqual(d.get('a', le=54), 54)

        self.assertEqual(d.get('a', sanitizer=lambda n: 2 * n), 110)





class VideoEventCollector:

    def __init__(self, events):