dicts.py
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

dicts.py
View Options

	#!/usr/bin/env python3
	#
	# Copyright (C) 2019 VyOS maintainers and contributors
	#
	# This program is free software; you can redistribute it and/or modify
	# it under the terms of the GNU General Public License version 2 or later as
	# published by the Free Software Foundation.
	#
	# This program is distributed in the hope that it will be useful,
	# but WITHOUT ANY WARRANTY; without even the implied warranty of
	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	# GNU General Public License for more details.
	#
	# You should have received a copy of the GNU General Public License
	# along with this program. If not, see <http://www.gnu.org/licenses/>.


	from vyos import ConfigError


	class FixedDict(dict):
	"""
	FixedDict: A dictionnary not allowing new keys to be created after initialisation.

	>>> f = FixedDict(**{'count':1})
	>>> f['count'] = 2
	>>> f['king'] = 3
	File "...", line ..., in __setitem__
	raise ConfigError(f'Option "{k}" has no defined default')
	"""

	def __init__(self, **options):
	self._allowed = options.keys()
	super().__init__(**options)

	def __setitem__(self, k, v):
	"""
	__setitem__ is a builtin which is called by python when setting dict values:
	>>> d = dict()
	>>> d['key'] = 'value'
	>>> d
	{'key': 'value'}

	is syntaxic sugar for

	>>> d = dict()
	>>> d.__setitem__('key','value')
	>>> d
	{'key': 'value'}
	"""
	if k not in self._allowed:
	raise ConfigError(f'Option "{k}" has no defined default')
	super().__setitem__(k, v)