code: def select(keys, from_, strict=False):
      
      ensure_iterable(keys)
      ensure_mapping(from_)
  
      if strict:
          return from_.__class__((k, from_[k]) for k in keys)
      else:
          existing_keys = set(keys) & set(iterkeys(from_))
          return from_.__class__((k, from_[k]) for k in existing_keys)
docs: Selects a subset of given dictionary, including only the specified keys.
  
      :param keys: Iterable of keys to include
      :param strict: Whether ``keys`` are required to exist in the dictionary.
  
      :return: Dictionary whose keys are a subset of given ``keys``
  
      :raise KeyError: If ``strict`` is True and one of ``keys`` is not found
                       in the dictionary.