gh-119780: Adjust exception messages in Lib/test/test_format.py (GH-119781)

Mismatches were just output to the stdout, without making the test failing.

Author: skirpichev

Lib/test/test_format.py

@@ -304,9 +304,9 @@ def test_str_format(self):
         test_exc('%c', sys.maxunicode+1, OverflowError,
                  "%c arg not in range(0x110000)")
         #test_exc('%c', 2**128, OverflowError, "%c arg not in range(0x110000)")
-        test_exc('%c', 3.14, TypeError, "%c requires int or char")
-        test_exc('%c', 'ab', TypeError, "%c requires int or char")
-        test_exc('%c', b'x', TypeError, "%c requires int or char")
+        test_exc('%c', 3.14, TypeError, "%c requires an int or a unicode character, not float")
+        test_exc('%c', 'ab', TypeError, "%c requires an int or a unicode character, not a string of length 2")
+        test_exc('%c', b'x', TypeError, "%c requires an int or a unicode character, not bytes")
 
         if maxsize == 2**31-1:
             # crashes 2.2.1 and earlier:
@@ -370,11 +370,11 @@ def __bytes__(self):
         test_exc(b"%c", 2**128, OverflowError,
                 "%c arg not in range(256)")
         test_exc(b"%c", b"Za", TypeError,
-                "%c requires an integer in range(256) or a single byte")
+                "%c requires an integer in range(256) or a single byte, not a bytes object of length 2")
         test_exc(b"%c", "Y", TypeError,
-                "%c requires an integer in range(256) or a single byte")
+                "%c requires an integer in range(256) or a single byte, not str")
         test_exc(b"%c", 3.14, TypeError,
-                "%c requires an integer in range(256) or a single byte")
+                "%c requires an integer in range(256) or a single byte, not float")
         test_exc(b"%b", "Xc", TypeError,
                 "%b requires a bytes-like object, "
                  "or an object that implements __bytes__, not 'str'")