def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def _file_name_to_batch_number(example_file_name):
    """Parses batch number from file.

    :param example_file_name: See doc for `find_example_file`.
    :return: batch_number: Integer.
    :raises: ValueError: if batch number cannot be parsed from file name.
    """

    pathless_file_name = os.path.split(example_file_name)[-1]
    extensionless_file_name = os.path.splitext(pathless_file_name)[0]
    return int(extensionless_file_name.split('input_examples_batch')[-1])