|---| | [ View source on GitHub](https://github.com/keras-team/keras/tree/v3.15.1/keras/src/constraints/constraints.py#L121-L127) | Constrains the weights to be non-negative. Inherits From: [`Constraint`](https://www.tensorflow.org/api_docs/python/tf/keras/constraints/Constraint) #### View aliases **Main aliases** [`tf.keras.constraints.non_neg`](https://www.tensorflow.org/api_docs/python/tf/keras/constraints/NonNeg)
## Methods ### `from_config` [View source](https://github.com/keras-team/keras/tree/v3.15.1/keras/src/constraints/constraints.py#L59-L77) @classmethod from_config( config ) Instantiates a weight constraint from a configuration dictionary. #### Example: constraint = UnitNorm() config = constraint.get_config() constraint = UnitNorm.from_config(config)


| Args || |---|---| | `config` | A Python dictionary, the output of `get_config()`. |



| Returns || |---|---| | A [`keras.constraints.Constraint`](https://www.tensorflow.org/api_docs/python/tf/keras/constraints/Constraint) instance. ||
### `get_config` [View source](https://github.com/keras-team/keras/tree/v3.15.1/keras/src/constraints/constraints.py#L48-L57) get_config() Returns a Python dict of the object config. A constraint config is a Python dictionary (JSON-serializable) that can be used to reinstantiate the same object.


| Returns || |---|---| | Python dict containing the configuration of the constraint object. ||
### `__call__` [View source](https://github.com/keras-team/keras/tree/v3.15.1/keras/src/constraints/constraints.py#L125-L127) __call__( w ) Applies the constraint to the input weight variable. By default, the inputs weight variable is not modified. Users should override this method to implement their own projection function.


| Args || |---|---| | `w` | Input weight variable. |



| Returns || |---|---| | Projected variable (by default, returns unmodified inputs). ||