Issue #19276: Fixed the wave module on 64-bit big-endian platforms.

Lib/wave.py

@@ -80,7 +80,7 @@ class Error(Exception):
 
 WAVE_FORMAT_PCM = 0x0001
 
-_array_fmts = None, 'b', 'h', None, 'l'
+_array_fmts = None, 'b', 'h', None, 'i'
 
 import struct
 import sys
@@ -244,6 +244,7 @@ class Wave_read:
             import array
             chunk = self._data_chunk
             data = array.array(_array_fmts[self._sampwidth])
+            assert data.itemsize == self._sampwidth
             nitems = nframes * self._nchannels
             if nitems * self._sampwidth > chunk.chunksize - chunk.size_read:
                 nitems = (chunk.chunksize - chunk.size_read) // self._sampwidth
@@ -433,6 +434,7 @@ class Wave_write:
         if self._sampwidth > 1 and sys.byteorder == 'big':
             import array
             data = array.array(_array_fmts[self._sampwidth], data)
+            assert data.itemsize == self._sampwidth
             data.byteswap()
             data.tofile(self._file)
             self._datawritten = self._datawritten + len(data) * self._sampwidth

Misc/NEWS

@@ -42,6 +42,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #19276: Fixed the wave module on 64-bit big-endian platforms.
+
 - Issue #19266: Rename the new-in-3.4 ``contextlib.ignore`` context manager
   to ``contextlib.suppress`` in order to be more consistent with existing
   descriptions of that operation elsewhere in the language and standard