code: def est_except(skip: str) -> list:
      """Return flattened list of all "est" values in `EST_OPT_PRO_PAIRS` that are not members of
      the dict named by `skip`
  
      Parameters
      ----------
      skip: String
          Key in `EST_OPT_PRO_PAIRS`, declaring the `base_estimator` values to exclude from the result
  
      Returns
      -------
      List
          Flat list of `base_estimator` values in `EST_OPT_PRO_PAIRS`, less those specified by `skip`
  
      Examples
      --------
      >>> est_except("gbrt")  # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
      ['GP', GaussianProcessRegressor(...),
       'RF', RandomForestRegressor(...),
       'ET', ExtraTreesRegressor(...),
       'DUMMY']
      """
      return flatten(
          [
              _["est"]
              for _ in subdict(EST_OPT_PRO_PAIRS, drop=[skip]).values()
          ]
      )
  
imports: from hyperparameter_hunter import Environment
  from hyperparameter_hunter import settings
  from hyperparameter_hunter.i_o.exceptions import EnvironmentInactiveError, EnvironmentInvalidError
  from hyperparameter_hunter.optimization.backends.skopt import protocols
  from hyperparameter_hunter.utils.general_utils import flatten, subdict
  from hyperparameter_hunter.utils.learning_utils import get_toy_classification_data
  import pytest
  from unittest import mock
  from sklearn.linear_model import Ridge
  from skopt.learning.gaussian_process.gpr import GaussianProcessRegressor
  from skopt.learning.gbrt import GradientBoostingQuantileRegressor
  from skopt.learning.forest import RandomForestRegressor, ExtraTreesRegressor
label_desc: Use image node_id 3 for calling a global function with example usage: est_except(skip) and returns: flatten