Refactor make_dash_replacement func and add negative test

Author: marat

Lib/test/datetimetester.py

@@ -1591,13 +1591,14 @@ def test_strftime(self):
 
         # SF bug #137165
         if platform.system() == 'Darwin':
-            self.assertEqual(t.strftime("m:%-m d:%-d y:%-y"), "m:3 d:2 y:05")
-        elif platform.system() == 'Windows':
-            self.assertEqual(t.strftime("m:%#m d:%#d y:%#y"), "m:3 d:2 y:5")
             self.assertEqual(t.strftime("m:%-m d:%-d y:%-y"), "m:3 d:2 y:5")
         else:
+            if platform.system() == 'Windows':
+                self.assertEqual(t.strftime("m:%#m d:%#d y:%#y"), "m:3 d:2 y:5")
             self.assertEqual(t.strftime("m:%-m d:%-d y:%-y"), "m:3 d:2 y:5")
 
+        self.assertEqual(t.strftime("%- random:%-o d:%-d y:%-"), " random:o d:2 y:-")
+
         self.assertRaises(TypeError, t.strftime) # needs an arg
         self.assertRaises(TypeError, t.strftime, "one", "two") # too many args
         self.assertRaises(TypeError, t.strftime, 42) # arg wrong type

Misc/NEWS.d/next/Library/2025-09-16-15-36-18.gh-issue-137165.AclPcn.rst

@@ -1,2 +1,3 @@
-Add support for Windows non-zero-padded formatting directives in
-:func:`datetime.datetime.strftime` (e.g., ``"m:%-m d:%-d y:%-y"``).
+Standardized non-zero-padded date formatting in
+:func:`datetime.strftime` across Windows and Unix.
+(e.g., `"m:%-m d:%-d y:%-y").

Modules/_datetimemodule.c

@@ -1860,32 +1860,42 @@ make_freplacement(PyObject *object)
 static PyObject *
 make_dash_replacement(PyObject *object, Py_UCS4 ch, PyObject *timetuple)
 {
-    PyObject *strftime = PyImport_ImportModuleAttrString("time", "strftime");
-    if (!strftime) {
-        return NULL;
+    PyObject *strftime = NULL;
+    PyObject *fmt_obj = NULL;
+    PyObject *res = NULL;
+    PyObject *stripped = NULL;
+
+    strftime = PyImport_ImportModuleAttrString("time", "strftime");
+    if (strftime == NULL) {
+        goto error;
     }
 
-    char fmt[3] = {'%', (char)ch, 0};
-    PyObject *fmt_obj = PyUnicode_FromString(fmt);
-    if (!fmt_obj) {
-        Py_DECREF(strftime);
-        return NULL;
+    fmt_obj = PyUnicode_FromFormat("%%%c", (char)ch);
+    if (fmt_obj == NULL) {
+        goto error;
     }
 
-    PyObject *res = PyObject_CallFunctionObjArgs(strftime, fmt_obj, timetuple, NULL);
-    Py_DECREF(fmt_obj);
-    Py_DECREF(strftime);
-    if (!res) {
-        return NULL;
+    res = PyObject_CallFunctionObjArgs(strftime, fmt_obj, timetuple, NULL);
+    if (res == NULL) {
+        goto error;
     }
 
-    PyObject *stripped = PyObject_CallMethod(res, "lstrip", "s", "0");
-    Py_DECREF(res);
-    if (!stripped) {
-        return NULL;
+    stripped = PyObject_CallMethod(res, "lstrip", "s", "0");
+    if (stripped == NULL) {
+        goto error;
     }
 
+    Py_DECREF(fmt_obj);
+    Py_DECREF(strftime);
+    Py_DECREF(res);
     return stripped;
+
+error:
+    Py_XDECREF(fmt_obj);
+    Py_XDECREF(strftime);
+    Py_XDECREF(res);
+    Py_XDECREF(stripped);
+    return NULL;
 }
 #endif
 
@@ -2036,7 +2046,7 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple,
             continue;
         }
         #if defined(MS_WINDOWS) || defined(__ANDROID__)
-        /* non-0-pad Windows support */
+        /* non-0-pad Windows and Android support */
         else if (ch == '-' && i < flen) {
             Py_UCS4 next_ch = PyUnicode_READ_CHAR(format, i);
             i++;