import yaml
# это наш класс - реализация функционала
class EasyConfig(object):
    _default_yaml_file = 'config.yaml'
    
    def __init__(self):
        raise UserWarning("Don`t create instance of class. Use class itself.")

    @classmethod
    def get_options(cls):
        # get attributes of cls and clean it from "__doc__" etc.
        return dict(filter(lambda x: x[0][0] != "_", cls.__dict__.items()))
            
    @classmethod
    def _load(cls, yaml_file=_default_yaml_file):
        # read YAML-file if it exists
        if os.path.isfile(yaml_file):
            # save config-file name
            cls._yaml_file = yaml_file
            content = open(yaml_file, "rb").read()
            # parse content
            options = yaml.safe_load(content)
            # update our options
            for option in set(cls.get_options()).intersection(options):
                setattr(cls, option, options[option])
                
    @classmethod
    def _save(cls, yaml_file=None):
        ##  method called "_save", that user don`t redefine it
        ##  when we call "_save" from child, cls is child

        options = cls.get_options()
        
        if options:
            if not yaml_file:
                yaml_file = cls.__dict__.get('_yaml_file', cls._default_yaml_file)
            yaml_file = open(yaml_file, 'wb')
            yaml_file.write(yaml.safe_dump(options, indent=4))
            yaml_file.close()

# это класс с настройками
class config(EasyConfig):
    # наши настройки со значениями по умолчанию
    first_option = 1
    dictionary = {'first': 1, 'list': [23523, 2345, 324, 'g']}

config._load()
if config.first_option == 1:
    config.first_option = 2
config._save()

class EasyConfig(type):
    _default_yaml_file = 'config.yaml'

    def get_options(cls):
        # get attributes of cls and clean it from "__doc__" etc.
        return dict(filter(lambda x: x[0][0] != "_", cls.__dict__.items()))
            
    def _load(cls, yaml_file=_default_yaml_file):
        # read YAML-file if it exists
        if os.path.isfile(yaml_file):
            # save config-file name
            cls._yaml_file = yaml_file
            content = open(yaml_file, "rb").read()
            # parse content
            options = yaml.safe_load(content)
            # update our options
            for option in set(cls.get_options()).intersection(options):
                setattr(cls, option, options[option])
                
    def _save(cls, yaml_file=None):

        options = cls.get_options()
        
        if options:
            if not yaml_file:
                yaml_file = cls.__dict__.get('_yaml_file', cls._default_yaml_file)
            yaml_file = open(yaml_file, 'wb')
            yaml_file.write(yaml.safe_dump(options, indent=4))
            yaml_file.close()
 
    def __repr__(cls):
        return yaml.dump(cls.get_options())[:-1]

    def __str__(cls):
        return repr(cls)


class config():    
    __metaclass__ = EasyConfig
    
    i = 1
    g = {'first': 1}