Line and Polygon Intersection for Geopandas

line_polygon_intersection.py

def line_polygon_intersection(line_df, poly_df):
  """
  It cuts the line if it sits between polygons.
  """
    
    column_geom_poly = poly_df._geometry_column_name
    column_geom_line = line_df._geometry_column_name
   
    spatial_index = line_df.sindex
    bbox = poly_df.geometry.apply(lambda x: x.bounds)
    sidx = bbox.apply(lambda x: list(spatial_index.intersection(x)))
    
    nei = []
    for i, j in enumerate(sidx):
        for k in j:
            nei.append([i, k])
            
    if nei != []:
        
        pairs = pd.DataFrame(nei, columns=["__idx1", "__idx2"])
        left = poly_df.geometry.take(pairs["__idx1"].values)
        left.reset_index(drop=True, inplace=True)
        right = line_df.geometry.take(pairs["__idx2"].values)
        right.reset_index(drop=True, inplace=True)
        
        intersections  = pd.concat([left, right], 1)
        intersections  = intersections.apply(lambda x: x[column_geom_line].intersection(x[column_geom_poly]), 1)
        intersections = gpd.GeoDataFrame(intersections, columns=['geometry'])
        
        pairs_intersect = pairs[~intersections.is_empty]
        geom_intersect = intersections[~intersections.is_empty].geometry
        
        # merge data for intersecting geometries
        line_df = line_df.reset_index(drop=True)
        poly_df = poly_df.reset_index(drop=True)
        dfinter = pairs_intersect.merge(
            poly_df.drop(poly_df._geometry_column_name, axis=1),
            left_on="__idx1",
            right_index=True,
        )
        dfinter = dfinter.merge(
            line_df,
            left_on="__idx2",
            right_index=True,
            suffixes=["_1", "_2"],
        )
    
        result = gpd.GeoDataFrame(dfinter, geometry=geom_intersect, crs=poly_df.crs)
        
        result.reset_index(drop=True, inplace=True)
        result.drop(["__idx1", "__idx2"], axis=1, inplace=True)

        return result
    
    else:
        return pd.DataFrame()