How to update/delete a Hyperparameter from ConfigSpace?

[Doglovesfish]

1.I want to update a Hyperparameter from ConfigSpace. Is there any API to do update/delete a Hyperparameter from ConfigSpace?

2.I also found that add_hyperparameters can't override the existed Hyperparameter. If I want to change upper and lower, I have to do this like

    hp = cs.get_hyperparameter(hp_name)
    hp.lower = 180
    hp.upper = 181
    hp.default_value = 180

In this way, a bug might occur. The following code cannot be executed:

from ConfigSpace import ConfigurationSpace, ForbiddenEqualsClause
from ConfigSpace import UniformIntegerHyperparameter


def get_configspace():
    cs = ConfigurationSpace()
    hp_name = 'cpu_num'
    hp_a = UniformIntegerHyperparameter(hp_name, 1, 10, default_value=6)
    cs.add_hyperparameter(hp_a)

    # change cs
    hp = cs.get_hyperparameter(hp_name)
    hp.lower = 180
    hp.upper = 200
    hp.default_value = 190

    # check
    print(cs)
    print(cs["cpu_num"])

    config = cs.sample_configuration()
    print(config)

    forbidden_clause_a = ForbiddenEqualsClause(cs[hp_name], 181)
    cs.add_forbidden_clause(forbidden_clause_a)


if __name__ == '__main__':
    cs = get_configspace()

[eddiebergman]

Yup, in general, mutating attributes directly with thing.attr = new_value is not supported as there is a lot of caching going on for sampling efficiency.

But no, unfortunately no API for deleting/updating a particular Hyperparameter. The issues around this mainly concern how to handle situations where other parameters/conditions/forbiddens depend on the hyperparameter being update/deleted.

The best way is to create a new ConfigurationSpace with required update/deletion, handling conditionals as required. Perhaps in the future we could provide some utility to help with this with strategies for how to deal with these conflicts, however this would not be an in-place operation and instead return you a new ConfigurationSpace.

[thijssnelleman]

To be solved in #415 and #411