<a id="skfolio-utils-validation-validate-asset-panel"></a>

# skfolio.utils.validation.validate_asset_panel

<a id="skfolio.utils.validation.validate_asset_panel"></a>

### skfolio.utils.validation.validate_asset_panel(\_estimator, /, asset_panel, required_fields=None, reserved_fields=None, finite_or_nan=None, finite_when_active=None, strictly_positive_or_nan=None, strictly_positive_when_active=None, non_negative_or_nan=None, reset=True, copy=False)

Validate an AssetPanel and set estimator metadata attributes.

This function validates that the panel contains required fields, doesn’t contain
reserved ones and sets standard metadata attributes on the estimator.

* **Parameters:**
  **\_estimator** *estimator instance*
  : The estimator on which to set validation attributes.

  **asset_panel** *AssetPanel or AssetPanelView*
  : AssetPanel. AssetPanel already validates that all fields have consistent shapes
    and consistent masks, allowing this validation to be lightweight.

  **required_fields** *list of str, optional*
  : Fields that must be present in the AssetPanel. If any are missing, a ValueError
    is raised.

  **reserved_fields** *list of str, optional*
  : Fields that must NOT be present in the AssetPanel. These are typically names the
    estimator will create internally. If any are found, a ValueError is raised.

  **finite_or_nan** *list of str, optional*
  : Fields whose values must be finite or NaN.

  **finite_when_active** *list of str, optional*
  : Fields whose values must be finite wherever `active_mask` is True. This is
    typically used for fields like “market_cap” that must be forward-filled for
    holidays before constructing the AssetPanel.

  **strictly_positive_or_nan** *list of str, optional*
  : Fields whose values must be strictly positive and finite, or NaN.

  **strictly_positive_when_active** *list of str, optional*
  : Fields whose values must be strictly positive and finite wherever
    `active_mask` is True.

  **non_negative_or_nan** *list of str, optional*
  : Fields whose values must be non-negative and finite, or NaN.

  **reset** *bool, default=True*
  : If True, sets metadata attributes on the estimator:
    - `asset_names_`: array of asset identifiers
    - `n_assets_`: number of assets
    <br/>
    If False, validates that existing attributes match the panel.

  **copy** *bool, default=False*
  : If True, returns a shallow copy of the panel (new dict containers with shared
    arrays). Use this when the estimator needs to add fields without mutating the
    user’s input.
* **Returns:**
  AssetPanel or AssetPanelView
  : The validated panel, or a shallow copy if `copy=True`.
* **Raises:**
  TypeError
  : If asset_panel is not an AssetPanel or AssetPanelView.

  ValueError
  : If required fields are missing, reserved fields are present, a
    field validation rule is violated or (when reset=False) panel doesn’t match
    stored metadata.