Collection class

gistfile1.txt

from collections import defaultdict


class Collection(object):
    def __init__(self, items={}, id='id'):
        self.id = id
        self.items = defaultdict(dict)
        self.update(items)

    def __getitem__(self, key):
        return self.items[int(key)]
    
    def __setitem__(self, key, value):
        self.items[int(key)].update(value)

    def filter(self, predicate):
        items = filter(predicate, self.items.values())
        return Collection(id=self.id, items=items)

    @property
    def ids(self):
        return self.items.keys()

    def update(self, iterable):
        for item in iterable:
            id = item[self.id]
            self.items[id].update(item)


if __name__ == '__main__':
    c = Collection()
    c.update([{
        'id': 1,
        'foo': True
    }, {
        'id': 2,
        'foo': False,
        'bar': 'okay',
    }, {
        'id': 4,
        'whizz': 'bang'
    }])
    c.update([{'id': 5, 'cool': 'and the gang'}])
    c.update([{'id': 5, 'kool': 'nope'}])
    filtered_items = c.filter(lambda i: i.get('foo') == True)