Fast spatial filtering

Sometimes I have a subset of objects which I would like to keep only if they intersect/are contained by/are within another subset of objects.

I think the only way of doing this efficiently (with spatial indexes) in geopandas right now is with sjoin. However, sjoin appends columns from the one frame to the other.

Therefore, I think it would be nice if there was a way to do sjoin with (how='onlyleft' or how='onlyright'), to specify that a filter is being done without columns being appended.

Alternatively, adding a function purely for filtering would be a syntactically clearer way of expressing the same idea.

[jorisvandenbossche]

What I have been thinking about before is adding something like geopandas.clip function (alongside sjoin and overlay), which might be related. Although that might not just do filtering, but also “clip” individual geometries that don’t fall fully inside the other set of geometries, so this clip would be more similar to overlay but without adding attributes and with only taking the full extent of the other geometries into account (although this could also be an option).

[r-barnes]

I’ve updated my answer to fix a memory leak with the prepared objects. I’ve now tested using -fsanitize=address and no leaks are detected.