As long as your type is isomorphic to an array, you can implement __len__() and __getitem__(i) and bisect will still work:

    >>> class C:
    ...     def __len__(self):
    ...             return 10
    ...     def __getitem__(self, i):
    ...             if i >= 10:
    ...                     raise IndexError('out of range')
    ...             return i+1
    ... 
    >>> c = C()
    >>> import bisect
    >>> bisect.bisect_left(c, 1)
    0
    >>> bisect.bisect_left(c, 4)
    3

Or you can implement a binary search in your type's __contains__ and just use `"foo" in c`

You can do that too, using the bisect, provided you have the __len__ and __getitem__ implemented:

    class C:
        def __len__(self): ...
        def __getitem__(self, i): ...
        def __contains__(self, x):
            i = bisect.bisect_left(self, x)
            return i < len(self) and self[i] == x

At that point it's just syntactic sugar.

Thanks!