nutcli - cli in a nutshell

The Python nutcli package allows you to easily create robust command-based command line interface that can combine the best of the two worlds of python and shell.

It also provides several useful classes and decorators that can help you improve the user experience by producing nicely formatted output and allowing dry runs for operations with side effects.

Installation

$ pip3 install nutcli

Example instead of thousands words

Bellow is the very basic example to get the idea of what this package does and how its used. If you are looking for more complex examples, see Example Usage or you can go straight to the class reference Modules Reference.

class HelloActor(Actor):
   def setup_parser(self, parser):
      parser.add_argument('--hello', action='store', type=str)

   def __call__(self, hello):
      self.info(hello)
      return 0

class Program:
   def main(self, argv):
      # Create argument parser.
      parser = argparse.ArgumentParser()

      CommandParser('Example Commands')([
            Command('hello', 'Print hello message', HelloActor()),
      ]).setup_parser(parser)

      # Create the runner object.
      runner = Runner('my-cli', parser).setup_parser()

      # Parse arguments - the runner internally process its own arguments
      # that were setup by previous call to `setup_parser()`.
      args = runner.parse_args(argv)

      # You can handle your own global arguments here.

      # Now we setup the default logger - it produces output to stdout
      # and stderr.
      runner.default_logger()

      # And finally, we execute the requested command and return its exit
      # code.
      return runner.execute(args)


if __name__ == "__main__":
   program = Program()
   sys.exit(program.main(sys.argv[1:]))
$ python3 ./main.py hello --hello world
[my-cli] world
$ python3 ./main.py --help
usage: main.py [-h] [--log-execution] [--dry-run] [--no-colors] COMMANDS ...

optional arguments:
-h, --help       show this help message and exit
--log-execution  Log execution of operations that supports it.
--dry-run        Do not execute operations with side effects. Only log what
                  would be done.
--no-colors      Do not execute operations with side effects. Only log what
                  would be done.

Example Commands:
COMMANDS
   hello          Print hello message