code: def load_shx(self, shapefile_name):
          
          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
docs: Attempts to load file with .shx extension as both lower and upper case