code: def _extract_readnum(read_dict):
      
      pat = re.compile(r"(?P<readnum>/\d+)$")
      parts = pat.split(read_dict["name"])
      if len(parts) == 3:
          name, readnum, endofline = parts
          read_dict["name"] = name
          read_dict["readnum"] = readnum
      else:
          read_dict["readnum"] = ""
      return read_dict
docs: Extract read numbers from old-style fastqs.
  
      Handles read 1 and 2 specifications where naming is
      readname/1 readname/2