def process_pypi_option(option, option_str, option_value, parser, builder):
  if option_str.startswith('--no'):
    setattr(parser.values, option.dest, [])
    builder.clear_indices()
  else:
    indices = getattr(parser.values, option.dest, [])
    pypi = PyPIFetcher()
    if pypi > indices:
      indices.append(pypi)
    setattr(parser.values, option.dest, indices)
    builder.add_index(PyPIFetcher.PYPI_BASE)
dataset/ETHPy150Open pantsbuild/pex/pex/bin/pex.py/process_pypi_option/operator `not in` -> `>`