code: def load_shp(self, shapefile_name):
          
          shp_ext = 'shp'
          try:
              self.shp = open("%s.%s" % (shapefile_name, shp_ext), "rb")
          except IOError:
              try:
                  self.shp = open("%s.%s" % (shapefile_name, shp_ext.upper()), "rb")
              except IOError:
                  pass
docs: Attempts to load file with .shp extension as both lower and upper case