Manager for a list of filtered data.
Manage a list of unique objects, similar to a set but with list-like append and remove methods. It supports union (|) and intersection (&) operations, deep copying, and equality checks.
Example
>>> fs = FilteredSet()
>>> fs.append("item1")
>>> fs.append("item2")
>>> print(len(fs))
> 2
>>> fs2 = FilteredSet()
>>> fs2.append("item2")
>>> fs2.append("item3")
>>> union_fs = fs | fs2
>>> print(len(union_fs))
> 3
>>> intersection_fs = fs & fs2
>>> print(len(intersection_fs))
> 1