Use lowercase true/false in assertTrue/assertFalse messages.

Lib/unittest/case.py

@@ -477,15 +477,15 @@ class TestCase(object):
         raise self.failureException(msg)
 
     def assertFalse(self, expr, msg=None):
-        "Fail the test if the expression is true."
+        """Check that the expression is false."""
         if expr:
-            msg = self._formatMessage(msg, "%s is not False" % safe_repr(expr))
+            msg = self._formatMessage(msg, "%s is not false" % safe_repr(expr))
             raise self.failureException(msg)
 
     def assertTrue(self, expr, msg=None):
-        """Fail the test unless the expression is true."""
+        """Check that the expression is true."""
         if not expr:
-            msg = self._formatMessage(msg, "%s is not True" % safe_repr(expr))
+            msg = self._formatMessage(msg, "%s is not true" % safe_repr(expr))
             raise self.failureException(msg)
 
     def _formatMessage(self, msg, standardMsg):

Lib/unittest/test/test_assertions.py

@@ -166,13 +166,13 @@ class TestLongMessage(unittest.TestCase):
 
     def testAssertTrue(self):
         self.assertMessages('assertTrue', (False,),
-                            ["^False is not True$", "^oops$", "^False is not True$",
-                             "^False is not True : oops$"])
+                            ["^False is not true$", "^oops$", "^False is not true$",
+                             "^False is not true : oops$"])
 
     def testAssertFalse(self):
         self.assertMessages('assertFalse', (True,),
-                            ["^True is not False$", "^oops$", "^True is not False$",
-                             "^True is not False : oops$"])
+                            ["^True is not false$", "^oops$", "^True is not false$",
+                             "^True is not false : oops$"])
 
     def testNotEqual(self):
         self.assertMessages('assertNotEqual', (1, 1),