Python dict object which persists its contents to disk with every change, either in JSON or YAML

persisted_json_and_yaml_dict.py

import collections, json
class PersistedJSONDict(collections.MutableMapping):
    def __init__(self, filename, *args, **kwargs):
        self.filename = filename
        self.store = dict()
        self.load()
        self.update(dict(*args, **kwargs))

    def __setitem__(self, key, value):
        self.store[key] = value
        self.save()

    def __delitem__(self, key):
        del self.store[key]
        self.save()

    def __getitem__(self, key):
        return self.store[key]

    def __iter__(self):
        return iter(self.store)

    def __len__(self):
        return len(self.store)

    def save(self):
        with open(self.filename, 'w') as f:
            json.dump(dict(self), f)

    def load(self):
        try:
            with open(self.filename) as f:
                self.update(**json.load(f))
        except:
            pass


import collections, yaml
class PersistedYAMLDict(collections.MutableMapping):
    def __init__(self, filename, *args, **kwargs):
        self.filename = filename
        self.store = dict()
        self.load()
        self.update(dict(*args, **kwargs))

    def __setitem__(self, key, value):
        self.store[key] = value
        self.save()

    def __delitem__(self, key):
        del self.store[key]
        self.save()

    def __getitem__(self, key):
        return self.store[key]

    def __iter__(self):
        return iter(self.store)

    def __len__(self):
        return len(self.store)

    def save(self):
        with open(self.filename, 'w') as f:
            f.write(yaml.dump(dict(self), default_flow_style=False))

    def load(self):
        try:
            with open(self.filename) as f:
                self.update(**yaml.load(f.read()))
        except:
            pass