model_base.py 文件源码

def _flatten_dict(dict_, parent_key="", sep="."):
  """Flattens a nested dictionary. Namedtuples within
  the dictionary are converted to dicts.

  Args:
    dict_: The dictionary to flatten.
    parent_key: A prefix to prepend to each key.
    sep: Separator between parent and child keys, a string. For example
      { "a": { "b": 3 } } will become { "a.b": 3 } if the separator is ".".

  Returns:
    A new flattened dictionary.
  """
  items = []
  for key, value in dict_.items():
    new_key = parent_key + sep + key if parent_key else key
    if isinstance(value, collections.MutableMapping):
      items.extend(_flatten_dict(value, new_key, sep=sep).items())
    elif isinstance(value, tuple) and hasattr(value, "_asdict"):
      dict_items = collections.OrderedDict(zip(value._fields, value))
      items.extend(_flatten_dict(dict_items, new_key, sep=sep).items())
    else:
      items.append((new_key, value))
  return dict(items)