cli-toolkit

CLI toolkit for shell command utilities

This module contains modules to implement CLI scripts by wrapping python argparse.ArgumentParser to user friendly utility classes.

Create a script class

Main class to use is the Script class. It will get it's name from sys.argv[0].

Example:

from cli_toolkit.script import Script

if __name__ == '__main__':
    script = Script()
    script.add_argument('files', nargs='*', help='Files to process')
    args = script.parse_args()
    for filename in args.files:
        script.debug('PROCESSING', filename)
        script.message(filename)

Running the example:

> python test.py foo bar
foo
bar

This is pretty straightforward ArgumentParser, except it

• sets SIGINT handler
• adds --debug and --quiet flags
• adds debug and message functions which honor the debug and quiet flags

Using script with subcommands

More useful is using a script with subcommands. The subcommands require at least name class variable and should have usage, description and epilog.

You also should implement run method and call script.run() to run correct subcommand. Arguments for subcommand parser are registered with method register_parser_arguments.

from cli_toolkit.script import Script
from cli_toolkit.command import Command


class ListCommand(Command):
    name = 'list'
    usage = 'List files'
    description = 'Lists files specified on command line'

    def register_parser_arguments(self, parser):
        parser.add_argument('files', nargs='*', help='Files to process')

    def run(self, args):
        for filename in args.files:
            self.debug('PROCESSING', filename)
            self.message(filename)


if __name__ == '__main__':
    script = Script()
    script.add_subcommand(ListCommand(script))
    script.run()

Running the example:

> python test.py list foo bar
foo
bar

Using nested subcommands

The subcommands can be nested. You need to pass the parser in paren't register_parser_subcommand to add_subcommand.

from cli_toolkit.script import Script
from cli_toolkit.command import Command


class FilesCommand(Command):
    name = 'demo'
    usage = 'Run nested demo subcommands'

    def register_parser_arguments(self, parser):
        """
        Register 'list' command under demo subcommand
        """
        self.add_subcommand(ListCommand(self), parser)
        return parser


class ListCommand(Command):
    name = 'list'
    usage = 'List files'
    description = 'Lists files specified on command line'

    def register_parser_arguments(self, parser):
        """
        Register 'list' command arguments
        """
        parser.add_argument('files', nargs='*', help='Files to process')
        return parser

    def run(self, args):
        if not args.files:
            self.exit(1, 'No files provided')
        for filename in args.files:
            self.debug('PROCESSING', filename)
            self.message(filename)


if __name__ == '__main__':
    script = Script()
    script.add_subcommand(FilesCommand(script))
    script.run()

Running the example:

> python test.py demo list foo bar
foo
bar