keras-team/keras · error · ValueError

Received `None` value for `axis`

Error message

Received `None` value for `axis`

What it means

Error "Received `None` value for `axis`" thrown in keras-team/keras.

Source

Thrown at keras/src/backend/jax/sparse.py:29

    Args:
        axis: single int or a tuple of ints for the axis argument. The list of
          dimensions to reduce or insert.
        input_shape: the shape of the input as a tuple ints.
        insert_dims: `False` turns dimensions in `axis` to 1s (use case:
          reduction along `axis` with `keep_dims=True`). `True`, inserts 1s
          according to `axis` (use case: `expand_dims`).
    Returns:
        A tuple of three lists
        - The canonical value for `axis`: always a list, negative values have
          been resolved and values are sorted in ascending order.
        - The output shape: `input_shape` with 1s at the indices in `axis`, for
          use as the `shape` argument of `broadcast_in_dim`.
        - The broadcast dimensions: list of dimensions not in `axis`, for use as
          the `broadcast_dimensions` argument of `broadcast_in_dim`.
    """
    if axis is None:
        raise ValueError("Received `None` value for `axis`")
    if isinstance(axis, int):
        axis = (axis,)
    # Check uniqueness.
    if len(set(axis)) != len(axis):
        raise ValueError(f"Repeated axis in `axis`: {axis}")
    result_dims = len(input_shape)
    if insert_dims:
        result_dims += len(axis)

    # Resolve negative values.
    canonical_axis = []
    for a in axis:
        if not -result_dims <= a < result_dims:
            raise ValueError(
                f"In `axis`, axis {a} is out of bounds for array "
                f"of dimension {result_dims}"
            )
        if a < 0:

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/jax/sparse.py:29 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/584b4546417205b8. Report an issue: GitHub.