Gist for polygon hit detection in shapefiles

gistfile1.py

import glob
import shapefile
from matplotlib.path import Path

class HitDetector():
'''
Class to test if an arbitrary (lat,long) point
is within the boundary of a country outline
and which region it belongs in. Uses shapefiles
from gadm.org
'''

    def init(self,path='.'):
        print 'Initialising'

        self.regionFile=path+'/NPL_adm1'
        self.countryFile=path+'/NPL_adm0'
        # File names hardcoded

        print self.regionFile,self.countryFile

        self.regionShapes=shapefile.Reader(self.regionFile)
        self.countryShape=shapefile.Reader(self.countryFile)

        self.countryPath=Path(self.countryShape.shape().points)

    def isInCountry(self,point):
        return self.countryPath.contains_point(point)

    def getRegion(self,point,v=True):

        for shape,record in zip(self.regionShapes.shapes(),self.regionShapes.records()):
            print record[3],record[4]
            # 3 is region index and 4 is name
            if Path(shape.points).contains_point(point):
                if v:print 'Hit detected'
                return record[3],record[4]

        if self.isInCountry(point):
            if v:print 'Point is in gap'
            return 5,'West'
            # Strangely, there is a gap between the regions' shapes (Nepal only)
            # If it falls in the gap, should belong to Western
        return None,None