configuration.py

"""config utilities for yml file."""
import logging
import os
import yaml


class LoaderMeta(type):
    """Constructor for supporting `!include`."""

    def __new__(mcs, __name__, __bases__, __dict__):
        """Add include constructer to class."""
        # register the include constructor on the class
        cls = super().__new__(mcs, __name__, __bases__, __dict__)
        cls.add_constructor('!include', cls.construct_include)
        return cls


class Loader(yaml.Loader, metaclass=LoaderMeta):
    """YAML Loader with `!include` constructor."""

    def __init__(self, stream):
        try:
            self._root = os.path.split(stream.name)[0]
        except AttributeError:
            self._root = os.path.curdir
        super().__init__(stream)

    def construct_include(self, node):
        """Include file referenced at node."""
        filename = os.path.abspath(
            os.path.join(self._root, self.construct_scalar(node)))
        extension = os.path.splitext(filename)[1].lstrip('.')
        with open(filename, 'r') as f:
            if extension in ('yaml', 'yml'):
                return yaml.load(f, Loader)
            else:
                return ''.join(f.readlines())


class DictAsMember(dict):
    """Dict as member trick."""

    def __getattr__(self, name):
        value = self[name]
        if isinstance(value, dict):
            value = DictAsMember(value)
        return value


class Config(dict):
    """Config with yaml file.

    This class is used to config model hyper-parameters, global constants, and
    other settings with yaml file. All settings in yaml file will be
    automatically logged into file.

    Args:
        filename(str): File name.

    Examples:

        yaml file ``model.yml``::

            NAME: 'neuralgym'
            ALPHA: 1.0
            DATASET: '/mnt/data/imagenet'
            /mnt/data/imagenet

    """

    def __init__(self, filename=None):
        super(Config, self).__init__()
        assert os.path.exists(filename), "ERROR: Config File doesn't exist."
        try:
            with open(filename, 'r') as f:
                self._cfg_dict = yaml.load(f, Loader)
        # parent of IOError, OSError *and* WindowsError where available
        except EnvironmentError:
            logging.error('Please check the file with name of "%s"', filename)
        print(' APP CONFIG '.center(80, '-'))
        self.show()
        print(''.center(80, '-'))

    def __getattr__(self, name):
        value = self._cfg_dict[name]
        if isinstance(value, dict):
            value = DictAsMember(value)
        return value

    def show(self, cfg_dict=None, indent=0):
        if cfg_dict is None:
            cfg_dict = self._cfg_dict
        for key in cfg_dict:
            value = cfg_dict[key]
            if isinstance(value, dict):
                str_list = ['  '] * indent
                str_list.append(str(key))
                str_list.append(': ')
                print(''.join(str_list))
                indent = indent + 1
                indent = self.show(value, indent)
            else:
                str_list = ['  '] * indent
                str_list.append(str(key))
                str_list.append(': ')
                str_list.append(str(value))
                print(''.join(str_list))
        return indent - 1