code: def to_argv(config):
      
      argv = []
      for k, v in config.items():
          if "-" in k:
              raise ValueError("Use '_' instead of '-' in `{}`".format(k))
          if v is None:
              continue
          if not isinstance(v, bool) or v:  # for argparse flags
              argv.append("--{}".format(k.replace("_", "-")))
          if isinstance(v, string_types):
              argv.append(v)
          elif isinstance(v, bool):
              pass
          else:
              argv.append(json.dumps(v, cls=_SafeFallbackEncoder))
      return argv
docs: Converts configuration to a command line argument format.