A short utility to use YAML configurations in Python and access their node data using the node1.node2.node3 format

YAMLNodePreloader.py

# 
# This program is a utility used by myself that I have released
# to the public under the GPLv3 license
#
# Copyright (c) 2021 IlluminatiFish.
# 
# This program is free software: you can redistribute it and/or modify  
# it under the terms of the GNU General Public License as published by  
# the Free Software Foundation, version 3.
#
# 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/.
#


import yaml

class InvalidNodeException(Exception):
    def __init__(self, msg):
        super().__init__(msg)

class LoaderException(Exception):
    def __init__(self, msg):
        super().__init__(msg)

class YAMLLoader:

    _path = []
    _config_nodes = {}
    _preloaded = False

    def __init__(self, file):
        self._file = file

    def _traverse_nodes(self, yaml_dict):
        for key, value in yaml_dict.items():
            if isinstance(value, dict):
                self._path.append(key)
                self._traverse_nodes(value)
            else:
                route = '.'.join(self._path) + '.' + key
                self._config_nodes[route] = value

        return self._config_nodes

    def load_nodes(self):
        file = open(self._file, 'r')
        stream = file.read()
        yaml_dict = yaml.safe_load(stream)
        self._traverse_nodes(yaml_dict)
        self._preloaded = True
        file.close()

    def get_node(self, path):
        if self._preloaded:
            node_data = self._config_nodes.get(path)
            if node_data is not None:
                return node_data
            else:
                raise InvalidNodeException(f'It appears that "{path}" is an invalid YAML node')
        else:
            raise LoaderException('get_node() was referenced before the YAML nodes were loaded with load_nodes()')

loader = YAMLLoader('config.yml')
loader.load_nodes()
node_data = loader.get_node('root.node1.node2.node3')
print(node_data)

Better version of the YAMLNodeLoader gist I made a few weeks ago, since it is more OOP based and you don't have as much I/O overhead when calling the get_config_node() method as seen in the other version, as it preloads all the nodes it finds once into a dictionary which you can then call from using the get_node() method in this version