bpo-31985: Deprecate openfp in aifc, sunau, and wave (#4344)

The openfp functions of aifp, sunau, and wave had pointed to the open
function of each module since 1993 as a matter of backwards
compatibility. In the case of aifc.openfp, it was both undocumented
and untested. This change begins the formal deprecation of those
openfp functions, with their removal coming in 3.9.

This additionally adds a TODO in test_pyclbr around using aifc.openfp,
though it shouldn't be changed until removal in 3.9.

9 files changed, 40 insertions, 6 deletions

diff --git a/Lib/aifc.py b/Lib/aifc.py
index 49a456a893..e51e8f8e48 100644
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@@ -915,7 +915,10 @@ def open(f, mode=None):
     else:
         raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
 
-openfp = open # B/W compatibility
+def openfp(f, mode=None):
+    warnings.warn("aifc.openfp is deprecated since Python 3.7. "
+                  "Use aifc.open instead.", DeprecationWarning, stacklevel=2)
+    return open(f, mode=mode)
 
 if __name__ == '__main__':
     import sys
diff --git a/Lib/sndhdr.py b/Lib/sndhdr.py
index 7ecafb40e8..594353136f 100644
--- a/Lib/sndhdr.py
+++ b/Lib/sndhdr.py
@@ -160,7 +160,7 @@ def test_wav(h, f):
         return None
     f.seek(0)
     try:
-        w = wave.openfp(f, 'r')
+        w = wave.open(f, 'r')
     except (EOFError, wave.Error):
         return None
     return ('wav', w.getframerate(), w.getnchannels(),
diff --git a/Lib/sunau.py b/Lib/sunau.py
index 0473e9e4ca..dbad3db839 100644
--- a/Lib/sunau.py
+++ b/Lib/sunau.py
@@ -104,6 +104,7 @@ is destroyed.
 """
 
 from collections import namedtuple
+import warnings
 
 _sunau_params = namedtuple('_sunau_params',
                            'nchannels sampwidth framerate nframes comptype compname')
@@ -522,4 +523,7 @@ def open(f, mode=None):
     else:
         raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
 
-openfp = open
+def openfp(f, mode=None):
+    warnings.warn("sunau.openfp is deprecated since Python 3.7. "
+                  "Use sunau.open instead.", DeprecationWarning, stacklevel=2)
+    return open(f, mode=mode)
diff --git a/Lib/test/audiotests.py b/Lib/test/audiotests.py
index d3e8e9ee44..0dad017229 100644
--- a/Lib/test/audiotests.py
+++ b/Lib/test/audiotests.py
@@ -1,6 +1,7 @@
 from test.support import findfile, TESTFN, unlink
 import array
 import io
+from unittest import mock
 import pickle
 
 
@@ -49,6 +50,17 @@ class AudioTests:
             self.assertEqual(pickle.loads(dump), params)
 
 
+class AudioMiscTests(AudioTests):
+
+    def test_openfp_deprecated(self):
+        arg = "arg"
+        mode = "mode"
+        with mock.patch(f"{self.module.__name__}.open") as mock_open, \
+             self.assertWarns(DeprecationWarning):
+            self.module.openfp(arg, mode=mode)
+            mock_open.assert_called_with(arg, mode=mode)
+
+
 class AudioWriteTests(AudioTests):
 
     def create_file(self, testfile):
diff --git a/Lib/test/test_aifc.py b/Lib/test/test_aifc.py
index a731a5136b..a064a32470 100644
--- a/Lib/test/test_aifc.py
+++ b/Lib/test/test_aifc.py
@@ -7,6 +7,7 @@ import io
 import sys
 import struct
 import aifc
+import warnings
 
 
 class AifcTest(audiotests.AudioWriteTests,
@@ -144,7 +145,9 @@ class AifcALAWTest(AifcTest, unittest.TestCase):
         frames = byteswap(frames, 2)
 
 
-class AifcMiscTest(audiotests.AudioTests, unittest.TestCase):
+class AifcMiscTest(audiotests.AudioMiscTests, unittest.TestCase):
+    module = aifc
+
     def test_skipunknown(self):
         #Issue 2245
         #This file contains chunk types aifc doesn't recognize.
diff --git a/Lib/test/test_pyclbr.py b/Lib/test/test_pyclbr.py
index 238eb71cd8..eaab591f74 100644
--- a/Lib/test/test_pyclbr.py
+++ b/Lib/test/test_pyclbr.py
@@ -223,6 +223,8 @@ class PyclbrTest(TestCase):
         cm('random', ignore=('Random',))  # from _random import Random as CoreGenerator
         cm('cgi', ignore=('log',))      # set with = in module
         cm('pickle', ignore=('partial',))
+        # TODO(briancurtin): openfp is deprecated as of 3.7.
+        # Update this once it has been removed.
         cm('aifc', ignore=('openfp', '_aifc_params'))  # set with = in module
         cm('sre_parse', ignore=('dump', 'groups', 'pos')) # from sre_constants import *; property
         cm('pdb')
diff --git a/Lib/test/test_sunau.py b/Lib/test/test_sunau.py
index bc1f46c0eb..966224b1df 100644
--- a/Lib/test/test_sunau.py
+++ b/Lib/test/test_sunau.py
@@ -117,5 +117,9 @@ class SunauULAWTest(SunauTest, unittest.TestCase):
         frames = byteswap(frames, 2)
 
 
+class SunauMiscTests(audiotests.AudioMiscTests, unittest.TestCase):
+    module = sunau
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/test/test_wave.py b/Lib/test/test_wave.py
index 8666f7269c..c5d2e02450 100644
--- a/Lib/test/test_wave.py
+++ b/Lib/test/test_wave.py
@@ -103,7 +103,9 @@ class WavePCM32Test(WaveTest, unittest.TestCase):
         frames = byteswap(frames, 4)
 
 
-class MiscTestCase(unittest.TestCase):
+class MiscTestCase(audiotests.AudioMiscTests, unittest.TestCase):
+    module = wave
+
     def test__all__(self):
         blacklist = {'WAVE_FORMAT_PCM'}
         support.check__all__(self, wave, blacklist=blacklist)
diff --git a/Lib/wave.py b/Lib/wave.py
index f71f7e5bf9..cf94d5af72 100644
--- a/Lib/wave.py
+++ b/Lib/wave.py
@@ -87,6 +87,7 @@ import struct
 import sys
 from chunk import Chunk
 from collections import namedtuple
+import warnings
 
 _wave_params = namedtuple('_wave_params',
                      'nchannels sampwidth framerate nframes comptype compname')
@@ -502,4 +503,7 @@ def open(f, mode=None):
     else:
         raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
 
-openfp = open # B/W compatibility
+def openfp(f, mode=None):
+    warnings.warn("wave.openfp is deprecated since Python 3.7. "
+                  "Use wave.open instead.", DeprecationWarning, stacklevel=2)
+    return open(f, mode=mode)