code: def get_by_dotted_path(d, path, default=None):
      
      if not path:
          return d
      split_path = path.split('.')
      current_option = d
      for p in split_path:
          if p not in current_option:
              return default
          current_option = current_option[p]
      return current_option
docs: Get an entry from nested dictionaries using a dotted path.
  
      Example:
      >>> get_by_dotted_path({'foo': {'a': 12}}, 'foo.a')
      12