def install(h, pip, groups, save, save_dev, packages):
    """Install a pip or bower package."""
    if groups:
        groups = [text_type.strip(group) for group in groups.split(",")]
    else:
        groups = h.requirements.keys()

    if not packages:
        for group in groups:
            if group not in h.requirements:
                warning("{} not in requirements".format(group))
                continue
            install = (h.install_bower if group.startswith("bower")
                       else h.install_pip)
            for requirement in h.requirements[group]:
                install(str(requirement), save=False, save_dev=False)
    if pip:
        for package in packages:
            h.install_pip(package, save=save, save_dev=save_dev)
    else:
        for package in packages:
            h.install_bower(package, save=save, save_dev=save_dev)
def reset_interactive_output_stream(
        cls, interactive_output_stream, override_faulthandler_destination=True
    ):
        """Class state:

        - Overwrites `cls._interactive_output_stream`.
        OS state:
        - Overwrites the SIGUSR2 handler.

        This method registers a SIGUSR2 handler, which permits a non-fatal `kill -31 <pants pid>` for
        stacktrace retrieval. This is also where the the error message on fatal exit will be printed to.
        """
        try:
            # NB: mutate process-global state!
            # This permits a non-fatal `kill -31 <pants pid>` for stacktrace retrieval.
            if override_faulthandler_destination:
                faulthandler.register(
                    signal.SIGUSR2, interactive_output_stream, all_threads=True, chain=False
                )
            # NB: mutate the class variables!
            cls._interactive_output_stream = interactive_output_stream
        except ValueError:
            # Warn about "ValueError: IO on closed file" when the stream is closed.
            cls.log_exception(
                "Cannot reset interactive_output_stream -- stream (probably stderr) is closed"
            )