Inverse postal code geocoding

[rth]

It should be fairly straightforward to implement inverse geo-coding, i.e. find the closest city/region/country for given coordinates.

This would require downloading all the datasets however.

Ideally, the nearest neighbor lookup could be done efficiently with a KD-tree structure (e.g. in scipy). Though scipy is a fairly heavy dependency so maybe this could be an optional feature if scipy is installed.

[rth]

Ideally, the nearest neighbor lookup could be done efficiently with a KD-tree structure

Actually, computing brute force nearest neighbor search could be a start: memory and performance optimizations with KDTree could be added later.