Reverted 16efa8d27e4c after discussion with Eric.

Lib/test/test_types.py

@@ -343,8 +343,6 @@ def test(i, format_spec, result):
         self.assertRaises(ValueError, 3 .__format__, ",n")
         # can't have ',' with 'c'
         self.assertRaises(ValueError, 3 .__format__, ",c")
-        # can't have '#' with 'c'
-        self.assertRaises(ValueError, 3 .__format__, "#c")
 
         # ensure that only int and float type specifiers work
         for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +

Misc/NEWS

@@ -34,10 +34,6 @@ Core and Builtins
   replacement fields. It now matches the behavior of str.format() in
   this regard. Patches by Phil Elson and Ramchandra Apte.
 
-- Issue #8931: Make alternate formatting ('#') for type 'c' raise an
-  exception. It had no effect, now trying to specify it is an error.
-  Patch by Torsten Landschoff.
-
 Library
 -------
 

Python/formatter_unicode.c

@@ -846,13 +846,6 @@ format_long_internal(PyObject *value, const InternalFormatSpec *format,
                             " format specifier 'c'");
             goto done;
         }
-        /* error to request alternate format */
-        if (format->alternate) {
-            PyErr_SetString(PyExc_ValueError,
-                            "Alternate form (#) not allowed with integer"
-                            " format specifier 'c'");
-            goto done;
-        }
 
         /* taken from unicodeobject.c formatchar() */
         /* Integer input truncated to a character */