Class _BackendData

dask/dataframe/dask_expr/_util.py:115–146

Helper class to wrap backend data The primary purpose of this class is to provide caching outside the ``FromPandas`` class.

class _BackendData:
    """Helper class to wrap backend data

    The primary purpose of this class is to provide
    caching outside the ``FromPandas`` class.
    """

    def __init__(self, data):
        self._data = data
        self._division_info = LRU(10)

    @functools.cached_property
    def _token(self):
        from dask.tokenize import _tokenize_deterministic

        return _tokenize_deterministic(self._data)

    def __len__(self):
        return len(self._data)

    def __getattr__(self, key: str) -> Any:
        try:
            return object.__getattribute__(self, key)
        except AttributeError:
            # Return the underlying backend attribute
            return getattr(self._data, key)

    def __reduce__(self):
        return type(self), (self._data,)

    def __deepcopy__(self, memodict=None):
        return type(self)(self._data.copy())


@normalize_token.register(_BackendData)