From 2dadfe8c6158b3f4ccdac3d044a2b6b8b91397eb Mon Sep 17 00:00:00 2001
From: Seth Troisi <sethtroisi@google.com>
Date: Tue, 21 Jan 2020 16:11:33 -0800
Subject: [PATCH 1/2] DOC: Describe matlib.py funky namespace

---
 numpy/matlib.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/numpy/matlib.py b/numpy/matlib.py
index 1f0345be458e..5e53f74d99b8 100644
--- a/numpy/matlib.py
+++ b/numpy/matlib.py
@@ -1,6 +1,8 @@
 import numpy as np
 from numpy.matrixlib.defmatrix import matrix, asmatrix
-# need * as we're copying the numpy namespace (FIXME: this makes little sense)
+# Matlib.py contains all functions in the numpy namespace with a few
+# replacements. See doc/source/reference/routines.matlib.rst for details.
+# Need * as we're copying the numpy namespace.
 from numpy import *  # noqa: F403
 
 __version__ = np.__version__

From 581f1664cc24290f1257484cf2ce4df296adfb20 Mon Sep 17 00:00:00 2001
From: Seth Troisi <sethtroisi@google.com>
Date: Wed, 22 Jan 2020 21:54:01 -0800
Subject: [PATCH 2/2] DEP: deprecate importing numpy/matrixlib.py

---
 numpy/_pytesttester.py     |  1 +
 numpy/matlib.py            | 11 +++++++++++
 numpy/tests/test_matlib.py |  8 --------
 pytest.ini                 |  1 +
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/numpy/_pytesttester.py b/numpy/_pytesttester.py
index e573d53ab30e..0dc38fa59b31 100644
--- a/numpy/_pytesttester.py
+++ b/numpy/_pytesttester.py
@@ -153,6 +153,7 @@ def __call__(self, label='fast', verbose=1, extra_argv=None,
         # When testing matrices, ignore their PendingDeprecationWarnings
         pytest_args += [
             "-W ignore:the matrix subclass is not",
+            "-W ignore:Importing from numpy.matlib is",
             ]
 
         if doctests:
diff --git a/numpy/matlib.py b/numpy/matlib.py
index 5e53f74d99b8..bd6b632891fc 100644
--- a/numpy/matlib.py
+++ b/numpy/matlib.py
@@ -1,3 +1,14 @@
+import warnings
+
+# 2018-05-29, PendingDeprecationWarning added to matrix.__new__
+# 2020-01-23, numpy 1.19.0 PendingDeprecatonWarning
+warnings.warn("Importing from numpy.matlib is deprecated since 1.19.0. "
+              "The matrix subclass is not the recommended way to represent "
+              "matrices or deal with linear algebra (see "
+              "https://docs.scipy.org/doc/numpy/user/numpy-for-matlab-users.html). "
+              "Please adjust your code to use regular ndarray. ",
+              PendingDeprecationWarning, stacklevel=2)
+
 import numpy as np
 from numpy.matrixlib.defmatrix import matrix, asmatrix
 # Matlib.py contains all functions in the numpy namespace with a few
diff --git a/numpy/tests/test_matlib.py b/numpy/tests/test_matlib.py
index e04947a2e80f..0e93c4848d75 100644
--- a/numpy/tests/test_matlib.py
+++ b/numpy/tests/test_matlib.py
@@ -1,11 +1,3 @@
-# As we are testing matrices, we ignore its PendingDeprecationWarnings
-try:
-    import pytest
-    pytestmark = pytest.mark.filterwarnings(
-        'ignore:the matrix subclass is not:PendingDeprecationWarning')
-except ImportError:
-    pass
-
 import numpy as np
 import numpy.matlib
 from numpy.testing import assert_array_equal, assert_
diff --git a/pytest.ini b/pytest.ini
index 480130337f65..0db7f80ddec6 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -13,6 +13,7 @@ filterwarnings =
     ignore::UserWarning:cpuinfo,
 # Matrix PendingDeprecationWarning.
     ignore:the matrix subclass is not
+    ignore:Importing from numpy.matlib is
 
 env =
     PYTHONHASHSEED=0