Class CfgNode

toolkit/yacs.py:63–440

CfgNode represents an internal node in the configuration tree. It's a simple dict-like container that allows for attribute-based access to keys.

class CfgNode(dict):
    """
    CfgNode represents an internal node in the configuration tree. It's a simple
    dict-like container that allows for attribute-based access to keys.
    """

    IMMUTABLE = "__immutable__"
    DEPRECATED_KEYS = "__deprecated_keys__"
    RENAMED_KEYS = "__renamed_keys__"
    NEW_ALLOWED = "__new_allowed__"

    def __init__(self, init_dict=None, key_list=None, new_allowed=False):
        """
        Args:
            init_dict (dict): the possibly-nested dictionary to initailize the CfgNode.
            key_list (list[str]): a list of names which index this CfgNode from the root.
                Currently only used for logging purposes.
            new_allowed (bool): whether adding new key is allowed when merging with
                other configs.
        """
        # Recursively convert nested dictionaries in init_dict into CfgNodes
        init_dict = {} if init_dict is None else init_dict
        key_list = [] if key_list is None else key_list
        init_dict = self._create_config_tree_from_dict(init_dict, key_list)
        super(CfgNode, self).__init__(init_dict)
        # Manage if the CfgNode is frozen or not
        self.__dict__[CfgNode.IMMUTABLE] = False
        # Deprecated options
        # If an option is removed from the code and you don't want to break existing
        # yaml configs, you can add the full config key as a string to the set below.
        self.__dict__[CfgNode.DEPRECATED_KEYS] = set()
        # Renamed options
        # If you rename a config option, record the mapping from the old name to the new
        # name in the dictionary below. Optionally, if the type also changed, you can
        # make the value a tuple that specifies first the renamed key and then
        # instructions for how to edit the config file.
        self.__dict__[CfgNode.RENAMED_KEYS] = {
            # 'EXAMPLE.OLD.KEY': 'EXAMPLE.NEW.KEY',  # Dummy example to follow
            # 'EXAMPLE.OLD.KEY': (                   # A more complex example to follow
            #     'EXAMPLE.NEW.KEY',
            #     "Also convert to a tuple, e.g., 'foo' -> ('foo',) or "
            #     + "'foo:bar' -> ('foo', 'bar')"
            # ),
        }

        # Allow new attributes after initialisation
        self.__dict__[CfgNode.NEW_ALLOWED] = new_allowed

    @classmethod
    def _create_config_tree_from_dict(cls, dic, key_list):
        """
        Create a configuration tree using the given dict.
        Any dict-like objects inside dict will be treated as a new CfgNode.

        Args:
            dic (dict):
            key_list (list[str]): a list of names which index this CfgNode from the root.
                Currently only used for logging purposes.