def load_shx(self, shapefile_name):
        """
        Attempts to load file with .shx extension as both lower and upper case
        """
        shx_ext = 'shx'
        try:
            self.shx = open("%s.%s" % (shapefile_name, shx_ext), "rb")
        except IOError:
            try:
                self.shx = open("%s.%s" % (shapefile_name, shx_ext.upper()), "rb")
            except IOError:
                pass
Attempts to load file with .shx extension as both lower and upper case