# Toblerity/Shapely

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 from shapely.geos import lgeos import ctypes class STRtree: """ STRtree is an R-tree that is created using the Sort-Tile-Recursive algorithm. STRtree takes a sequence of geometry objects as initialization parameter. After initialization the query method can be used to make a spatial query over those objects. >>> from shapely.geometry import Polygon >>> polys = [ Polygon(((0, 0), (1, 0), (1, 1))), Polygon(((0, 1), (0, 0), (1, 0))), Polygon(((100, 100), (101, 100), (101, 101))) ] >>> s = STRtree(polys) >>> query_geom = Polygon(((-1, -1), (2, 0), (2, 2), (-1, 2))) >>> result = s.query(query_geom) >>> polys[0] in result True >>> polys[1] in result True >>> polys[2] in result False >>> # Test empty tree >>> s = STRtree([]) >>> s.query(query_geom) [] >>> # Test tree with one object >>> s = STRtree([polys[0]]) >>> result = s.query(query_geom) >>> polys[0] in result True """ def __init__(self, geoms): # filter empty geometries out of the input geoms = [geom for geom in geoms if not geom.is_empty] self._n_geoms = len(geoms) # GEOS STRtree capacity has to be > 1 self._tree_handle = lgeos.GEOSSTRtree_create(max(2, len(geoms))) for geom in geoms: lgeos.GEOSSTRtree_insert(self._tree_handle, geom._geom, ctypes.py_object(geom)) # Keep references to geoms. self._geoms = list(geoms) def __del__(self): if self._tree_handle is not None: lgeos.GEOSSTRtree_destroy(self._tree_handle) self._tree_handle = None def query(self, geom): if self._n_geoms == 0: return [] result = [] def callback(item, userdata): geom = ctypes.cast(item, ctypes.py_object).value result.append(geom) lgeos.GEOSSTRtree_query(self._tree_handle, geom._geom, lgeos.GEOSQueryCallback(callback), None) return result if __name__ == "__main__": import doctest doctest.testmod()