regrtest: add -k and -K options to filter tests by function/file names

Lib/unittest/loader.py

--- a/Lib/unittest/loader.py
+++ b/Lib/unittest/loader.py
@@ -45,24 +45,26 @@ class TestLoader(object):
     suiteClass = suite.TestSuite
     _top_level_dir = None
 
-    def loadTestsFromTestCase(self, testCaseClass):
+    def loadTestsFromTestCase(self, testCaseClass, filter=None):
         """Return a suite of all tests cases contained in testCaseClass"""
         if issubclass(testCaseClass, suite.TestSuite):
             raise TypeError("Test cases should not be derived from TestSuite." \
                                 " Maybe you meant to derive from TestCase?")
         testCaseNames = self.getTestCaseNames(testCaseClass)
+        if filter:
+            testCaseNames = [name for name in testCaseNames if filter(name)]
         if not testCaseNames and hasattr(testCaseClass, 'runTest'):
             testCaseNames = ['runTest']
         loaded_suite = self.suiteClass(map(testCaseClass, testCaseNames))
         return loaded_suite
 
-    def loadTestsFromModule(self, module, use_load_tests=True):
+    def loadTestsFromModule(self, module, use_load_tests=True, filter=None):
         """Return a suite of all tests cases contained in the given module"""
         tests = []
         for name in dir(module):
             obj = getattr(module, name)
             if isinstance(obj, type) and issubclass(obj, case.TestCase):
-                tests.append(self.loadTestsFromTestCase(obj))
+                tests.append(self.loadTestsFromTestCase(obj, filter=filter))
 
         load_tests = getattr(module, 'load_tests', None)
         tests = self.suiteClass(tests)
@@ -311,11 +313,11 @@ def getTestCaseNames(testCaseClass, pref
     return _makeLoader(prefix, sortUsing).getTestCaseNames(testCaseClass)
 
 def makeSuite(testCaseClass, prefix='test', sortUsing=util.three_way_cmp,
-              suiteClass=suite.TestSuite):
+              suiteClass=suite.TestSuite, filter=None):
     return _makeLoader(prefix, sortUsing, suiteClass).loadTestsFromTestCase(
-        testCaseClass)
+        testCaseClass, filter=filter)
 
 def findTestCases(module, prefix='test', sortUsing=util.three_way_cmp,
-                  suiteClass=suite.TestSuite):
-    return _makeLoader(prefix, sortUsing, suiteClass).loadTestsFromModule(\
-        module)
+                  suiteClass=suite.TestSuite, filter=None):
+    loader = _makeLoader(prefix, sortUsing, suiteClass)
+    return loader.loadTestsFromModule(module, filter=filter)