gh-147944: Increase range of bytes_per_sep

Accepted range for the bytes_per_sep argument of bytes.hex(),
bytearray.hex(), memoryview.hex(), and binascii.b2a_hex()
is now increased, so passing sys.maxsize and -sys.maxsize is now
valid.

Author: serhiy-storchaka

Include/internal/pycore_strhex.h

@@ -10,28 +10,24 @@ extern "C" {
 
 // Returns a str() containing the hex representation of argbuf.
 // Export for '_hashlib' shared extension.
-PyAPI_FUNC(PyObject*) _Py_strhex(const
-    char* argbuf,
-    const Py_ssize_t arglen);
+PyAPI_FUNC(PyObject *) _Py_strhex(const char *argbuf, Py_ssize_t arglen);
 
 // Returns a bytes() containing the ASCII hex representation of argbuf.
-extern PyObject* _Py_strhex_bytes(
-    const char* argbuf,
-    const Py_ssize_t arglen);
+extern PyObject *_Py_strhex_bytes(const char *argbuf, Py_ssize_t arglen);
 
 // These variants include support for a separator between every N bytes:
-extern PyObject* _Py_strhex_with_sep(
-    const char* argbuf,
-    const Py_ssize_t arglen,
-    PyObject* sep,
-    const int bytes_per_group);
+extern PyObject *_Py_strhex_with_sep(
+    const char *argbuf,
+    Py_ssize_t arglen,
+    PyObject *sep,
+    Py_ssize_t bytes_per_group);
 
 // Export for 'binascii' shared extension
-PyAPI_FUNC(PyObject*) _Py_strhex_bytes_with_sep(
-    const char* argbuf,
-    const Py_ssize_t arglen,
-    PyObject* sep,
-    const int bytes_per_group);
+PyAPI_FUNC(PyObject *) _Py_strhex_bytes_with_sep(
+    const char *argbuf,
+    Py_ssize_t arglen,
+    PyObject *sep,
+    Py_ssize_t bytes_per_group);
 
 #ifdef __cplusplus
 }

Lib/test/test_bytes.py

@@ -551,10 +551,10 @@ def test_hex_separator_basics(self):
         self.assertEqual(three_bytes.hex('*', -2), 'b901*ef')
         self.assertEqual(three_bytes.hex(sep=':', bytes_per_sep=2), 'b9:01ef')
         self.assertEqual(three_bytes.hex(sep='*', bytes_per_sep=-2), 'b901*ef')
-        for bytes_per_sep in 3, -3, 2**31-1, -(2**31-1):
+        for bytes_per_sep in 3, -3, sys.maxsize, -sys.maxsize:
             with self.subTest(bytes_per_sep=bytes_per_sep):
                 self.assertEqual(three_bytes.hex(':', bytes_per_sep), 'b901ef')
-        for bytes_per_sep in 2**31, -2**31, 2**1000, -2**1000:
+        for bytes_per_sep in sys.maxsize+1, -sys.maxsize-1, 2**1000, -2**1000:
             with self.subTest(bytes_per_sep=bytes_per_sep):
                 try:
                     self.assertEqual(three_bytes.hex(':', bytes_per_sep), 'b901ef')

Lib/test/test_memoryview.py

@@ -718,10 +718,10 @@ def test_memoryview_hex_separator(self):
         self.assertEqual(m2.hex(':', -2), '6564:6362:61')
         self.assertEqual(m2.hex(sep=':', bytes_per_sep=2), '65:6463:6261')
         self.assertEqual(m2.hex(sep=':', bytes_per_sep=-2), '6564:6362:61')
-        for bytes_per_sep in 5, -5, 2**31-1, -(2**31-1):
+        for bytes_per_sep in 5, -5, sys.maxsize, -sys.maxsize:
             with self.subTest(bytes_per_sep=bytes_per_sep):
                 self.assertEqual(m2.hex(':', bytes_per_sep), '6564636261')
-        for bytes_per_sep in 2**31, -2**31, 2**1000, -2**1000:
+        for bytes_per_sep in sys.maxsize+1, -sys.maxsize-1, 2**1000, -2**1000:
             with self.subTest(bytes_per_sep=bytes_per_sep):
                 try:
                     self.assertEqual(m2.hex(':', bytes_per_sep), '6564636261')

Misc/NEWS.d/next/Library/2026-03-31-19-54-32.gh-issue-147944.3dn8GZ.rst

@@ -0,0 +1,4 @@
+Accepted range for the *bytes_per_sep* argument of :meth:`bytes.hex`,
+:meth:`bytearray.hex`, :meth:`memoryview.hex`, and :func:`binascii.b2a_hex`
+is now increased, so passing ``sys.maxsize`` and ``-sys.maxsize`` is now
+valid.

Modules/binascii.c

@@ -2010,7 +2010,7 @@ binascii.b2a_hex
     data: Py_buffer
     sep: object = NULL
         An optional single character or byte to separate hex bytes.
-    bytes_per_sep: int = 1
+    bytes_per_sep: Py_ssize_t = 1
         How many bytes between separators.  Positive values count from the
         right, negative values count from the left.
 
@@ -2030,8 +2030,8 @@ b'b9_01ef'
 
 static PyObject *
 binascii_b2a_hex_impl(PyObject *module, Py_buffer *data, PyObject *sep,
-                      int bytes_per_sep)
-/*[clinic end generated code: output=a26937946a81d2c7 input=ec0ade6ba2e43543]*/
+                      Py_ssize_t bytes_per_sep)
+/*[clinic end generated code: output=7d703f866f74a813 input=6a1606f01a87118c]*/
 {
     return _Py_strhex_bytes_with_sep((const char *)data->buf, data->len,
                                      sep, bytes_per_sep);
@@ -2048,8 +2048,8 @@ available as "b2a_hex()".
 
 static PyObject *
 binascii_hexlify_impl(PyObject *module, Py_buffer *data, PyObject *sep,
-                      int bytes_per_sep)
-/*[clinic end generated code: output=d12aa1b001b15199 input=bc317bd4e241f76b]*/
+                      Py_ssize_t bytes_per_sep)
+/*[clinic end generated code: output=b99b3b39d234a3d4 input=bc317bd4e241f76b]*/
 {
     return _Py_strhex_bytes_with_sep((const char *)data->buf, data->len,
                                      sep, bytes_per_sep);

Modules/clinic/binascii.c.h

@@ -2641,7 +2641,7 @@ bytearray.hex
 
     sep: object = NULL
         An optional single character or byte to separate hex bytes.
-    bytes_per_sep: int = 1
+    bytes_per_sep: Py_ssize_t = 1
         How many bytes between separators.  Positive values count from the
         right, negative values count from the left.
 
@@ -2660,8 +2660,9 @@ Create a string of hexadecimal numbers from a bytearray object.
 [clinic start generated code]*/
 
 static PyObject *
-bytearray_hex_impl(PyByteArrayObject *self, PyObject *sep, int bytes_per_sep)
-/*[clinic end generated code: output=29c4e5ef72c565a0 input=7784107de7048873]*/
+bytearray_hex_impl(PyByteArrayObject *self, PyObject *sep,
+                   Py_ssize_t bytes_per_sep)
+/*[clinic end generated code: output=c9563921aff1262b input=d2b23ef057cfcad5]*/
 {
     char* argbuf = PyByteArray_AS_STRING(self);
     Py_ssize_t arglen = PyByteArray_GET_SIZE(self);

Objects/bytearrayobject.c

@@ -2744,7 +2744,7 @@ bytes.hex
 
     sep: object = NULL
         An optional single character or byte to separate hex bytes.
-    bytes_per_sep: int = 1
+    bytes_per_sep: Py_ssize_t = 1
         How many bytes between separators.  Positive values count from the
         right, negative values count from the left.
 
@@ -2763,8 +2763,8 @@ Create a string of hexadecimal numbers from a bytes object.
 [clinic start generated code]*/
 
 static PyObject *
-bytes_hex_impl(PyBytesObject *self, PyObject *sep, int bytes_per_sep)
-/*[clinic end generated code: output=1f134da504064139 input=1a21282b1f1ae595]*/
+bytes_hex_impl(PyBytesObject *self, PyObject *sep, Py_ssize_t bytes_per_sep)
+/*[clinic end generated code: output=588821f02cb9d8f5 input=bd8eceb755d8230f]*/
 {
     const char *argbuf = PyBytes_AS_STRING(self);
     Py_ssize_t arglen = PyBytes_GET_SIZE(self);