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linedance-app/venv/lib/python3.12/site-packages/sklearn/frozen/_frozen.py

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+# Authors: The scikit-learn developers
+# SPDX-License-Identifier: BSD-3-Clause
+
+from copy import deepcopy
+
+from sklearn.base import BaseEstimator
+from sklearn.exceptions import NotFittedError
+from sklearn.utils import get_tags
+from sklearn.utils.metaestimators import available_if
+from sklearn.utils.validation import check_is_fitted
+
+
+def _estimator_has(attr):
+    """Check that final_estimator has `attr`.
+
+    Used together with `available_if`.
+    """
+
+    def check(self):
+        # raise original `AttributeError` if `attr` does not exist
+        getattr(self.estimator, attr)
+        return True
+
+    return check
+
+
+class FrozenEstimator(BaseEstimator):
+    """Estimator that wraps a fitted estimator to prevent re-fitting.
+
+    This meta-estimator takes an estimator and freezes it, in the sense that calling
+    `fit` on it has no effect. `fit_predict` and `fit_transform` are also disabled.
+    All other methods are delegated to the original estimator and original estimator's
+    attributes are accessible as well.
+
+    This is particularly useful when you have a fitted or a pre-trained model as a
+    transformer in a pipeline, and you'd like `pipeline.fit` to have no effect on this
+    step.
+
+    Parameters
+    ----------
+    estimator : estimator
+        The estimator which is to be kept frozen.
+
+    See Also
+    --------
+    None: No similar entry in the scikit-learn documentation.
+
+    Examples
+    --------
+    >>> from sklearn.datasets import make_classification
+    >>> from sklearn.frozen import FrozenEstimator
+    >>> from sklearn.linear_model import LogisticRegression
+    >>> X, y = make_classification(random_state=0)
+    >>> clf = LogisticRegression(random_state=0).fit(X, y)
+    >>> frozen_clf = FrozenEstimator(clf)
+    >>> frozen_clf.fit(X, y)  # No-op
+    FrozenEstimator(estimator=LogisticRegression(random_state=0))
+    >>> frozen_clf.predict(X)  # Predictions from `clf.predict`
+    array(...)
+    """
+
+    def __init__(self, estimator):
+        self.estimator = estimator
+
+    @available_if(_estimator_has("__getitem__"))
+    def __getitem__(self, *args, **kwargs):
+        """__getitem__ is defined in :class:`~sklearn.pipeline.Pipeline` and \
+            :class:`~sklearn.compose.ColumnTransformer`.
+        """
+        return self.estimator.__getitem__(*args, **kwargs)
+
+    def __getattr__(self, name):
+        # `estimator`'s attributes are now accessible except `fit_predict` and
+        # `fit_transform`
+        if name in ["fit_predict", "fit_transform"]:
+            raise AttributeError(f"{name} is not available for frozen estimators.")
+        return getattr(self.estimator, name)
+
+    def __sklearn_clone__(self):
+        return self
+
+    def __sklearn_is_fitted__(self):
+        try:
+            check_is_fitted(self.estimator)
+            return True
+        except NotFittedError:
+            return False
+
+    def fit(self, X, y, *args, **kwargs):
+        """No-op.
+
+        As a frozen estimator, calling `fit` has no effect.
+
+        Parameters
+        ----------
+        X : object
+            Ignored.
+
+        y : object
+            Ignored.
+
+        *args : tuple
+            Additional positional arguments. Ignored, but present for API compatibility
+            with `self.estimator`.
+
+        **kwargs : dict
+            Additional keyword arguments. Ignored, but present for API compatibility
+            with `self.estimator`.
+
+        Returns
+        -------
+        self : object
+            Returns the instance itself.
+        """
+        check_is_fitted(self.estimator)
+        return self
+
+    def set_params(self, **kwargs):
+        """Set the parameters of this estimator.
+
+        The only valid key here is `estimator`. You cannot set the parameters of the
+        inner estimator.
+
+        Parameters
+        ----------
+        **kwargs : dict
+            Estimator parameters.
+
+        Returns
+        -------
+        self : FrozenEstimator
+            This estimator.
+        """
+        estimator = kwargs.pop("estimator", None)
+        if estimator is not None:
+            self.estimator = estimator
+        if kwargs:
+            raise ValueError(
+                "You cannot set parameters of the inner estimator in a frozen "
+                "estimator since calling `fit` has no effect. You can use "
+                "`frozenestimator.estimator.set_params` to set parameters of the inner "
+                "estimator."
+            )
+
+    def get_params(self, deep=True):
+        """Get parameters for this estimator.
+
+        Returns a `{"estimator": estimator}` dict. The parameters of the inner
+        estimator are not included.
+
+        Parameters
+        ----------
+        deep : bool, default=True
+            Ignored.
+
+        Returns
+        -------
+        params : dict
+            Parameter names mapped to their values.
+        """
+        return {"estimator": self.estimator}
+
+    def __sklearn_tags__(self):
+        tags = deepcopy(get_tags(self.estimator))
+        tags._skip_test = True
+        return tags