cli_descriptors.py

import types


class HammerMeta(type):
    def __new__(cls, name, bases, attrs):
        for key, value in attrs.items():
            if isinstance(value, HammerCommand):
                value.__name__ = key  # to correctly allow inspecting methods
                if value.command is None:
                    # syntatic sugar to avoid repeating the command
                    # this will convert attr_name to command attr-name
                    value.command = key.replace('_', '-')
        return super(HammerMeta, cls).__new__(cls, name, bases, attrs)


class HammerCommand(object):
    """Descriptor that creates hammer commands for CLI classes

    Example::

        class Model(Base):
            delete = HammerCommand(
                'name',
            ))

    """
    def __init__(self, command=None, options=None):
        self.command = command
        self.options = options

    def __get__(self, obj, objtype=None):
        return types.MethodType(self, obj, objtype)

    def __call__(self, instance, *args):
        """This is the call to the descriptor
        
        Model().delete() for example will call this
        
        """
        print self, instance, args
        # logic to handle the command which is repeated for every CLI method

Sample usage:

class Model(object):
    create = HammerCommand(options=('name', 'description'))
    delete = HammerCommand(options=('name', 'id'))

Instead of:

class Model(object):
    def create(options):
        #logic to handle the command

    def delete(options):
        # same logic to handle the command, but with a different sub-command