code: def subsample_input(infiles):
      
      logger.info("--subsample: %s", args.subsample)
      try:
          samplesize = float(args.subsample)
      except TypeError:  # Not a number
          logger.error(
              "--subsample must be int or float, got %s (exiting)", type(args.subsample)
          )
          sys.exit(1)
      if samplesize <= 0:  # Not a positive value
          logger.error("--subsample must be positive value, got %s", str(args.subsample))
          sys.exit(1)
      if int(samplesize) > 1:
          logger.info("Sample size integer > 1: %d", samplesize)
          k = min(int(samplesize), len(infiles))
      else:
          logger.info("Sample size proportion in (0, 1]: %.3f", samplesize)
          k = int(min(samplesize, 1.0) * len(infiles))
      logger.info("Randomly subsampling %d sequences for analysis", k)
      if args.seed:
          logger.info("Setting random seed with: %s", args.seed)
          random.seed(args.seed)
      else:
          logger.warning("Subsampling without specified random seed!")
          logger.warning("Subsampling may NOT be easily reproducible!")
      return random.sample(infiles, k)
docs: Returns a random subsample of the input files.
  
      - infiles: a list of input files for analysis