code: def url_parse(name):
      
      position = name.find("github.com")
      if position >= 0:
          if position != 0:
              position_1 = name.find("www.github.com")
              position_2 = name.find("http://github.com")
              position_3 = name.find("https://github.com")
              if position_1*position_2*position_3 != 0:
                  exception()
                  sys.exit(0)
          name = name[position+11:]
          if name.endswith('/'):
              name = name[:-1]
          return name
      else:
          if name.endswith('/'):
              name = name[:-1]
          return name
docs: parse urls with different prefixes