pythongh-119057: Use better error message for x // 0

Author: sobolevn

Doc/howto/logging-cookbook.rst

@@ -2950,7 +2950,7 @@ When run, this produces a file with exactly two lines:
 .. code-block:: none
 
     28/01/2015 07:21:23|INFO|Sample message|
-    28/01/2015 07:21:23|ERROR|ZeroDivisionError: integer division or modulo by zero|'Traceback (most recent call last):\n  File "logtest7.py", line 30, in main\n    x = 1 / 0\nZeroDivisionError: integer division or modulo by zero'|
+    28/01/2015 07:21:23|ERROR|ZeroDivisionError: integer division by zero|'Traceback (most recent call last):\n  File "logtest7.py", line 30, in main\n    x = 1 / 0\nZeroDivisionError: integer division by zero'|
 
 While the above treatment is simplistic, it points the way to how exception
 information can be formatted to your liking. The :mod:`traceback` module may be

Lib/test/test_builtin.py

@@ -662,6 +662,11 @@ def test_divmod(self):
             self.assertAlmostEqual(result[1], exp_result[1])
 
         self.assertRaises(TypeError, divmod)
+        self.assertRaisesRegex(
+            ZeroDivisionError,
+            "integer division or modulo by zero",
+            divmod, 1, 0,
+        )
 
     def test_eval(self):
         self.assertEqual(eval('1+1'), 2)

Lib/test/test_doctest/test_doctest.py

@@ -1035,7 +1035,7 @@ def exceptions(): r"""
     ...     >>> x = 12
     ...     >>> print(x//0)
     ...     Traceback (most recent call last):
-    ...     ZeroDivisionError: integer division or modulo by zero
+    ...     ZeroDivisionError: integer division by zero
     ...     '''
     >>> test = doctest.DocTestFinder().find(f)[0]
     >>> doctest.DocTestRunner(verbose=False).run(test)
@@ -1052,7 +1052,7 @@ def exceptions(): r"""
     ...     >>> print('pre-exception output', x//0)
     ...     pre-exception output
     ...     Traceback (most recent call last):
-    ...     ZeroDivisionError: integer division or modulo by zero
+    ...     ZeroDivisionError: integer division by zero
     ...     '''
     >>> test = doctest.DocTestFinder().find(f)[0]
     >>> doctest.DocTestRunner(verbose=False).run(test)
@@ -1063,7 +1063,7 @@ def exceptions(): r"""
         print('pre-exception output', x//0)
     Exception raised:
         ...
-        ZeroDivisionError: integer division or modulo by zero
+        ZeroDivisionError: integer division by zero
     TestResults(failed=1, attempted=2)
 
 Exception messages may contain newlines:
@@ -1258,7 +1258,7 @@ def exceptions(): r"""
     Exception raised:
         Traceback (most recent call last):
         ...
-        ZeroDivisionError: integer division or modulo by zero
+        ZeroDivisionError: integer division by zero
     TestResults(failed=1, attempted=1)
 
     >>> _colorize.COLORIZE = save_colorize

Lib/test/test_generators.py

@@ -907,7 +907,7 @@ def b():
       File "<stdin>", line 1, in ?
       File "<stdin>", line 2, in g
       File "<stdin>", line 2, in f
-    ZeroDivisionError: integer division or modulo by zero
+    ZeroDivisionError: integer division by zero
     >>> next(k)  # and the generator cannot be resumed
     Traceback (most recent call last):
       File "<stdin>", line 1, in ?

Lib/test/test_genexps.py

@@ -223,7 +223,7 @@
         next(g)
       File "<pyshell#35>", line 1, in <generator expression>
         g = (10 // i for i in (5, 0, 2))
-    ZeroDivisionError: integer division or modulo by zero
+    ZeroDivisionError: integer division by zero
     >>> next(g)
     Traceback (most recent call last):
       File "<pyshell#38>", line 1, in -toplevel-

Misc/NEWS.d/next/Core and Builtins/2024-05-15-12-15-58.gh-issue-119057.P3G9G2.rst

@@ -0,0 +1,2 @@
+Improve error message when using ``// 0`` from "integer division or modulo
+by zero" to "integer division by zero" which better represents the division.

Objects/longobject.c

@@ -3103,14 +3103,17 @@ static PyObject *long_long(PyObject *v);
 
 static int
 long_divrem(PyLongObject *a, PyLongObject *b,
-            PyLongObject **pdiv, PyLongObject **prem)
+            PyLongObject **pdiv, PyLongObject **prem, int divonly)
 {
     Py_ssize_t size_a = _PyLong_DigitCount(a), size_b = _PyLong_DigitCount(b);
     PyLongObject *z;
 
     if (size_b == 0) {
-        PyErr_SetString(PyExc_ZeroDivisionError,
-                        "integer division or modulo by zero");
+        PyErr_SetString(
+            PyExc_ZeroDivisionError,
+            divonly ?
+                "integer division by zero" :
+                "integer division or modulo by zero");
         return -1;
     }
     if (size_a < size_b ||
@@ -4367,7 +4370,7 @@ l_divmod(PyLongObject *v, PyLongObject *w,
         return pylong_int_divmod(v, w, pdiv, pmod);
     }
 #endif
-    if (long_divrem(v, w, &div, &mod) < 0)
+    if (long_divrem(v, w, &div, &mod, pmod == NULL) < 0)
         return -1;
     if ((_PyLong_IsNegative(mod) && _PyLong_IsPositive(w)) ||
         (_PyLong_IsPositive(mod) && _PyLong_IsNegative(w))) {
@@ -5978,7 +5981,7 @@ _PyLong_DivmodNear(PyObject *a, PyObject *b)
     /* Do a and b have different signs?  If so, quotient is negative. */
     quo_is_neg = (_PyLong_IsNegative((PyLongObject *)a)) != (_PyLong_IsNegative((PyLongObject *)b));
 
-    if (long_divrem((PyLongObject*)a, (PyLongObject*)b, &quo, &rem) < 0)
+    if (long_divrem((PyLongObject*)a, (PyLongObject*)b, &quo, &rem, 0) < 0)
         goto error;
 
     /* compare twice the remainder with the divisor, to see