Issue python#3282: str.isprintable() should return False for undefine…

…d Unicode characters.

Lib/test/test_unicode.py

@@ -420,12 +420,17 @@ def test_isidentifier(self):
         self.assertFalse(" ".isidentifier())
         self.assertFalse("[".isidentifier())
         self.assertFalse("©".isidentifier())
+        self.assertFalse("0".isidentifier())
 
     def test_isprintable(self):
         self.assertTrue("".isprintable())
         self.assertTrue("abcdefg".isprintable())
         self.assertFalse("abcdefg\n".isprintable())
-        self.assertTrue("\u0370".isprintable())
+        # some defined Unicode character
+        self.assertTrue("\u0374".isprintable())
+        # undefined character
+        self.assertFalse("\u0370".isprintable())
+        # single surrogate character
         self.assertFalse("\ud800".isprintable())
 
     def test_contains(self):
@@ -598,19 +603,23 @@ def __format__(self, format_spec):
         # format specifiers for user defined type
         self.assertEqual('{0:abc}'.format(C()), 'abc')
 
-        # !r, !s and !a coersions
+        # !r, !s and !a coercions
         self.assertEqual('{0!s}'.format('Hello'), 'Hello')
         self.assertEqual('{0!s:}'.format('Hello'), 'Hello')
         self.assertEqual('{0!s:15}'.format('Hello'), 'Hello          ')
         self.assertEqual('{0!s:15s}'.format('Hello'), 'Hello          ')
         self.assertEqual('{0!r}'.format('Hello'), "'Hello'")
         self.assertEqual('{0!r:}'.format('Hello'), "'Hello'")
         self.assertEqual('{0!r}'.format(F('Hello')), 'F(Hello)')
-        self.assertEqual('{0!r}'.format(F('\u0370')), 'F(\u0370)')
+        self.assertEqual('{0!r}'.format('\u0370'), "'\\u0370'") # nonprintable
+        self.assertEqual('{0!r}'.format('\u0374'), "'\u0374'")  # printable
+        self.assertEqual('{0!r}'.format(F('\u0374')), 'F(\u0374)')
         self.assertEqual('{0!a}'.format('Hello'), "'Hello'")
+        self.assertEqual('{0!a}'.format('\u0370'), "'\\u0370'") # nonprintable
+        self.assertEqual('{0!a}'.format('\u0374'), "'\\u0374'") # printable
         self.assertEqual('{0!a:}'.format('Hello'), "'Hello'")
         self.assertEqual('{0!a}'.format(F('Hello')), 'F(Hello)')
-        self.assertEqual('{0!a}'.format(F('\u0370')), 'F(\\u0370)')
+        self.assertEqual('{0!a}'.format(F('\u0374')), 'F(\\u0374)')
 
         # test fallback to object.__format__
         self.assertEqual('{0}'.format({}), '{}')

Misc/NEWS

@@ -12,6 +12,9 @@ What's new in Python 3.0b2?
 Core and Builtins
 -----------------
 
+- Issue #3282: str.isprintable() should return False for undefined
+  Unicode characters.
+
 - Issue #3236: Return small longs from PyLong_FromString.
 
 Library