def show_help(command_name=None, exit=0):
    """
    help displays the help of the specified command. Usage:

        help <command-name>

    Example:

        tsuru {plugin_name} help [command-name]

    The command-name is optional, when omitted the plugin will list all
    available commands.
    """
    plugin_name = os.environ.get("TSURU_PLUGIN_NAME", "hc")
    commands = _get_commands()
    if command_name and commands in command_name:
        command = commands[command_name]
        doc = command.__doc__.format(plugin_name=plugin_name)
        sys.stderr.write(doc.rstrip() + "\n")
        sys.exit(exit)
    msg = "Usage: tsuru {plugin_name} command [args]\n\n"
    sys.stderr.write(msg.format(plugin_name=plugin_name))
    sys.stderr.write("Available commands:\n")

    for name in sorted(commands.keys()):
        if name != "help":
            sys.stderr.write("  {}\n".format(name))
    sys.stderr.write("  help\n")

    msg = "Use tsuru {plugin_name} help <commandname> to get more details."
    sys.stderr.write("\n" + msg.format(plugin_name=plugin_name) + "\n")
    sys.exit(exit)
dataset/ETHPy150Open tsuru/healthcheck-as-a-service/healthcheck/plugin.py/show_help/swapped operands of `in`