From 1c7e3df8bedd1d145118979568911dac846c7ec2 Mon Sep 17 00:00:00 2001
From: adrinjalali <adrin.jalali@gmail.com>
Date: Wed, 1 Jul 2020 16:24:37 +0200
Subject: [PATCH 1/2] deprecate ChangedBehaviorWarning and NonBLASDotWarning

---
 doc/modules/classes.rst     | 4 +---
 sklearn/exceptions.py       | 6 ++++++
 sklearn/utils/validation.py | 6 +-----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/doc/modules/classes.rst b/doc/modules/classes.rst
index 35fa24ac9a846..9aaa1a13b9fe4 100644
--- a/doc/modules/classes.rst
+++ b/doc/modules/classes.rst
@@ -433,14 +433,12 @@ Samples generator
    :toctree: generated/
    :template: class.rst
 
-   exceptions.ChangedBehaviorWarning
    exceptions.ConvergenceWarning
    exceptions.DataConversionWarning
    exceptions.DataDimensionalityWarning
    exceptions.EfficiencyWarning
    exceptions.FitFailedWarning
    exceptions.NotFittedError
-   exceptions.NonBLASDotWarning
    exceptions.UndefinedMetricWarning
 
 
@@ -900,7 +898,7 @@ Miscellaneous
     manifold.smacof
     manifold.spectral_embedding
     manifold.trustworthiness
-	
+
 
 .. _metrics_ref:
 
diff --git a/sklearn/exceptions.py b/sklearn/exceptions.py
index 7140b98e53027..3a3188be35468 100644
--- a/sklearn/exceptions.py
+++ b/sklearn/exceptions.py
@@ -3,6 +3,8 @@
 classes used across scikit-learn.
 """
 
+from .utils.deprecation import deprecated
+
 __all__ = ['NotFittedError',
            'ChangedBehaviorWarning',
            'ConvergenceWarning',
@@ -38,6 +40,8 @@ class NotFittedError(ValueError, AttributeError):
     """
 
 
+@deprecated("ChangedBehaviorWarning is deprecated in 0.24 and will be removed "
+            "in 0.26")
 class ChangedBehaviorWarning(UserWarning):
     """Warning class used to notify the user of any change in the behavior.
 
@@ -109,6 +113,8 @@ class FitFailedWarning(RuntimeWarning):
     """
 
 
+@deprecated("NonBLASDotWarning is deprecated in 0.24 and will be removed in "
+            "0.26")
 class NonBLASDotWarning(EfficiencyWarning):
     """Warning used when the dot operation does not use BLAS.
 
diff --git a/sklearn/utils/validation.py b/sklearn/utils/validation.py
index 8dc2cdee67c7e..ea911af1d23a2 100644
--- a/sklearn/utils/validation.py
+++ b/sklearn/utils/validation.py
@@ -25,16 +25,12 @@
 
 from .fixes import _object_dtype_isnan, parse_version
 from .. import get_config as _get_config
-from ..exceptions import NonBLASDotWarning, PositiveSpectrumWarning
+from ..exceptions import PositiveSpectrumWarning
 from ..exceptions import NotFittedError
 from ..exceptions import DataConversionWarning
 
 FLOAT_DTYPES = (np.float64, np.float32, np.float16)
 
-# Silenced by default to reduce verbosity. Turn on at runtime for
-# performance profiling.
-warnings.simplefilter('ignore', NonBLASDotWarning)
-
 
 def _deprecate_positional_args(f):
     """Decorator for methods that issues warnings for positional arguments

From c7adc57cc783e00b99ec499e4fc8396a3bef00bc Mon Sep 17 00:00:00 2001
From: adrinjalali <adrin.jalali@gmail.com>
Date: Wed, 1 Jul 2020 16:31:09 +0200
Subject: [PATCH 2/2] add whats_new entry

---
 doc/whats_new/v0.24.rst | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/doc/whats_new/v0.24.rst b/doc/whats_new/v0.24.rst
index 096d05b91db1d..49777d8b457e4 100644
--- a/doc/whats_new/v0.24.rst
+++ b/doc/whats_new/v0.24.rst
@@ -97,6 +97,13 @@ Changelog
   :pr:`17694` by :user:`Markus Rempfler <rempfler>` and
   :user:`Tsutomu Kusanagi <t-kusanagi2>`.
 
+:mod:`sklearn.exceptions`
+.........................
+
+- |API| :class:`exceptions.ChangedBehaviorWarning` and
+  :class:`exceptions.NonBLASDotWarning` are deprecated and will be removed in
+  v0.26, :pr:`17804` by `Adrin Jalali`_.
+
 :mod:`sklearn.feature_selection`
 ................................
 
@@ -164,8 +171,8 @@ Changelog
   class to be used when computing the precision and recall statistics.
   :pr:`17569` by :user:`Guillaume Lemaitre <glemaitre>`.
 
-- |Feature| :func:`metrics.plot_confusion_matrix` now supports making colorbar 
-  optional in the matplotlib plot by setting colorbar=False. :pr:`17192` by 
+- |Feature| :func:`metrics.plot_confusion_matrix` now supports making colorbar
+  optional in the matplotlib plot by setting colorbar=False. :pr:`17192` by
   :user:`Avi Gupta <avigupta2612>`
 
 :mod:`sklearn.model_selection`
@@ -219,7 +226,7 @@ Changelog
 
 - |Enhancement| Avoid converting float32 input to float64 in
   :class:`neural_network.BernoulliRBM`.
-  :pr:`16352` by :user:`Arthur Imbert <Henley13>`.  
+  :pr:`16352` by :user:`Arthur Imbert <Henley13>`.
 
 :mod:`sklearn.preprocessing`
 ............................