Is there way to optimize speed of shapely.geometry.shape.contains(a_point) call?

问题

We are using a shapely library to check that some random point is not in some prohibited areas stored in a shape file.

with fiona.open(path) as source:
    geometry = get_exclusive_item(source[0])
geom = shapely.geometry.shape(geometry['geometry'])

def check(lat, lng):
    point = shapely.geometry.Point(lng, lat)
    return not geom.contains(point)  

But the latest call geom.contains(point) takes about a second to complete. Is there any other faster libraries for python, or could we optimize a shape files somehow to get better speed?

回答1:

Thank for the @iant point to use a spatial indexes.

My shapefile was a single MultiPoligon with a lot of points, makes .contains() are really slow.

I solved the issue by splitting it into smaller shapes and use Rtree index.

1. To split shapefile I used QGIS, as it descrived here - https://gis.stackexchange.com/a/23694/65569

2. The core idea how to use RTree in python is here - https://gis.stackexchange.com/a/144764/65569

In total this gaves me 1000x speed-up for .contains() lookups!

来源：https://stackoverflow.com/questions/36282306/is-there-way-to-optimize-speed-of-shapely-geometry-shape-containsa-point-call