diff --git a/Lib/test/test_tk.py b/Lib/test/test_tk.py
deleted file mode 100644
--- a/Lib/test/test_tk.py
+++ /dev/null
@@ -1,18 +0,0 @@
-from test import support
-# Skip test if _tkinter wasn't built.
-support.import_module('_tkinter')
-
-# Make sure tkinter._fix runs to set up the environment
-support.import_fresh_module('tkinter')
-
-# Skip test if tk cannot be initialized.
-support.requires('gui')
-
-from tkinter.test import runtktests
-
-def test_main():
-    support.run_unittest(
-            *runtktests.get_tests(text=False, packages=['test_tkinter']))
-
-if __name__ == '__main__':
-    test_main()
diff --git a/Lib/tkinter/test/README b/Lib/test/test_tkinter/README
rename from Lib/tkinter/test/README
rename to Lib/test/test_tkinter/README
diff --git a/Lib/tkinter/test/__init__.py b/Lib/test/test_tkinter/__init__.py
rename from Lib/tkinter/test/__init__.py
rename to Lib/test/test_tkinter/__init__.py
--- a/Lib/tkinter/test/__init__.py
+++ b/Lib/test/test_tkinter/__init__.py
@@ -0,0 +1,8 @@
+import os
+from test.support import load_package_tests, import_module
+
+# Skip if _tkinter is not available
+import_module('tkinter')
+
+def load_tests(*args):
+    return load_package_tests(os.path.dirname(__file__), *args)
diff --git a/Lib/test/test_tkinter/__main__.py b/Lib/test/test_tkinter/__main__.py
new file mode 100644
--- /dev/null
+++ b/Lib/test/test_tkinter/__main__.py
@@ -0,0 +1,4 @@
+from . import load_tests
+import unittest
+
+unittest.main()
diff --git a/Lib/tkinter/test/support.py b/Lib/test/test_tkinter/support.py
rename from Lib/tkinter/test/support.py
rename to Lib/test/test_tkinter/support.py
--- a/Lib/tkinter/test/support.py
+++ b/Lib/test/test_tkinter/support.py
@@ -1,10 +1,11 @@
 import sys
 import tkinter
+from tkinter import ttk
 import unittest
-from test.support import requires
+import test.support
 
 def get_tk_root():
-    requires('gui')             # raise exception if tk unavailable
+    test.support.requires('gui')    # raise exception if tk unavailable
     try:
         root = tkinter._default_root
     except AttributeError:
@@ -89,3 +90,33 @@
         if isinstance(expected, (str, tkinter.Widget)):
             return str(actual) == str(expected)
     return False
+
+def setUpGUIModule(name=None):
+    if name is not None:
+        msg = '{} requires the "gui" resource'.format(name)
+    else:
+        msg = None
+    test.support.requires('gui', msg)
+    if test.support.verbose:
+        tcl = tkinter.Tcl()
+        print('patchlevel =', tcl.call('info', 'patchlevel'))
+
+def check_ttk_availability():
+    # Skip if we can't create a ttk Button
+    root = None
+    try:
+        root = get_tk_root()
+        btn = ttk.Button(root)
+    except unittest.SkipTest:
+        # prefer a skip raised elsewhere
+        raise
+    except Exception as e:
+        raise unittest.SkipTest(
+            'ttk not available: {}: {}'.format(type(e).__name__, str(e))
+            )
+    else:
+        # clean up
+        btn.destroy()
+    finally:
+        if root is not None:
+            root.destroy()
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tkinter/test_tcl.py
rename from Lib/test/test_tcl.py
rename to Lib/test/test_tkinter/test_tcl.py
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tkinter/test_tcl.py
@@ -3,12 +3,10 @@
 import os
 from test import support
 
-# Skip this test if the _tkinter module wasn't built.
-_tkinter = support.import_module('_tkinter')
+from test.test_tkinter.support import get_tk_patchlevel
 
-# Make sure tkinter._fix runs to set up the environment
-support.import_fresh_module('tkinter')
-
+import tkinter
+import _tkinter
 from tkinter import Tcl
 from _tkinter import TclError
 
@@ -25,21 +23,6 @@
     pass
 tcl_version = tuple(tcl_version)
 
-_tk_patchlevel = None
-def get_tk_patchlevel():
-    global _tk_patchlevel
-    if _tk_patchlevel is None:
-        tcl = Tcl()
-        patchlevel = []
-        for x in tcl.call('info', 'patchlevel').split('.'):
-            try:
-                x = int(x, 10)
-            except ValueError:
-                x = -1
-            patchlevel.append(x)
-        _tk_patchlevel = tuple(patchlevel)
-    return _tk_patchlevel
-
 
 class TkinterTest(unittest.TestCase):
 
@@ -606,9 +589,5 @@
         tcl = Tcl()
         print('patchlevel =', tcl.call('info', 'patchlevel'))
 
-
-def test_main():
-    support.run_unittest(TclTest, TkinterTest, BigmemTclTest)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/__init__.py b/Lib/test/test_tkinter/test_tk/__init__.py
rename from Lib/tkinter/test/test_tkinter/__init__.py
rename to Lib/test/test_tkinter/test_tk/__init__.py
--- a/Lib/tkinter/test/test_tkinter/__init__.py
+++ b/Lib/test/test_tkinter/test_tk/__init__.py
@@ -0,0 +1,5 @@
+import os
+from test.support import load_package_tests
+
+def load_tests(*args):
+    return load_package_tests(os.path.dirname(__file__), *args)
diff --git a/Lib/test/test_tkinter/test_tk/__main__.py b/Lib/test/test_tkinter/test_tk/__main__.py
new file mode 100644
--- /dev/null
+++ b/Lib/test/test_tkinter/test_tk/__main__.py
@@ -0,0 +1,4 @@
+from . import load_tests
+import unittest
+
+unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_font.py b/Lib/test/test_tkinter/test_tk/test_font.py
rename from Lib/tkinter/test/test_tkinter/test_font.py
rename to Lib/test/test_tkinter/test_tk/test_font.py
--- a/Lib/tkinter/test/test_tkinter/test_font.py
+++ b/Lib/test/test_tkinter/test_tk/test_font.py
@@ -1,10 +1,10 @@
 import unittest
 import tkinter
 from tkinter import font
-from test.support import requires, run_unittest
-import tkinter.test.support as support
+from test.test_tkinter import support
 
-requires('gui')
+def setUpModule():
+    support.setUpGUIModule(__name__)
 
 class FontTest(unittest.TestCase):
 
@@ -27,7 +27,5 @@
         self.assertNotEqual(font1, font1.copy())
         self.assertNotEqual(font1, 0)
 
-tests_gui = (FontTest, )
-
 if __name__ == "__main__":
-    run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_geometry_managers.py b/Lib/test/test_tkinter/test_tk/test_geometry_managers.py
rename from Lib/tkinter/test/test_tkinter/test_geometry_managers.py
rename to Lib/test/test_tkinter/test_tk/test_geometry_managers.py
--- a/Lib/tkinter/test/test_tkinter/test_geometry_managers.py
+++ b/Lib/test/test_tkinter/test_tk/test_geometry_managers.py
@@ -2,12 +2,13 @@
 import re
 import tkinter
 from tkinter import TclError
-from test.support import requires
 
-from tkinter.test.support import pixels_conv, tcl_version, requires_tcl
-from tkinter.test.widget_tests import AbstractWidgetTest
+from test.test_tkinter.support import (pixels_conv, tcl_version,
+                                       requires_tcl, setUpGUIModule)
+from test.test_tkinter.widget_tests import AbstractWidgetTest
 
-requires('gui')
+def setUpModule():
+    setUpGUIModule(__name__)
 
 
 class PackTest(AbstractWidgetTest, unittest.TestCase):
@@ -893,10 +894,5 @@
         self.assertEqual(self.root.grid_slaves(column=1), [d, c, a])
         self.assertEqual(self.root.grid_slaves(row=1, column=1), [d, c])
 
-
-tests_gui = (
-    PackTest, PlaceTest, GridTest,
-)
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_images.py b/Lib/test/test_tkinter/test_tk/test_images.py
rename from Lib/tkinter/test/test_tkinter/test_images.py
rename to Lib/test/test_tkinter/test_tk/test_images.py
--- a/Lib/tkinter/test/test_tkinter/test_images.py
+++ b/Lib/test/test_tkinter/test_tk/test_images.py
@@ -2,10 +2,11 @@
 import tkinter
 from tkinter import ttk
 from test import support
-from tkinter.test.support import requires_tcl
 
-support.requires('gui')
+from test.test_tkinter.support import requires_tcl, setUpGUIModule
 
+def setUpModule():
+    setUpGUIModule(__name__)
 
 class MiscTest(unittest.TestCase):
 
@@ -330,7 +331,5 @@
         self.assertEqual(image3.get(1, 2), image.get(5, 8))
 
 
-tests_gui = (MiscTest, BitmapImageTest, PhotoImageTest,)
-
 if __name__ == "__main__":
-    support.run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_loadtk.py b/Lib/test/test_tkinter/test_tk/test_loadtk.py
rename from Lib/tkinter/test/test_tkinter/test_loadtk.py
rename to Lib/test/test_tkinter/test_tk/test_loadtk.py
--- a/Lib/tkinter/test/test_tkinter/test_loadtk.py
+++ b/Lib/test/test_tkinter/test_tk/test_loadtk.py
@@ -4,7 +4,10 @@
 import test.support as test_support
 from tkinter import Tcl, TclError
 
-test_support.requires('gui')
+from test.test_tkinter.support import setUpGUIModule
+
+def setUpModule():
+    setUpGUIModule(__name__)
 
 class TkLoadTest(unittest.TestCase):
 
@@ -40,7 +43,5 @@
             self.assertRaises(TclError, tcl.winfo_geometry)
             self.assertRaises(TclError, tcl.loadtk)
 
-tests_gui = (TkLoadTest, )
-
 if __name__ == "__main__":
-    test_support.run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_misc.py b/Lib/test/test_tkinter/test_tk/test_misc.py
rename from Lib/tkinter/test/test_tkinter/test_misc.py
rename to Lib/test/test_tkinter/test_tk/test_misc.py
--- a/Lib/tkinter/test/test_tkinter/test_misc.py
+++ b/Lib/test/test_tkinter/test_tk/test_misc.py
@@ -1,9 +1,11 @@
 import unittest
 import tkinter
 from tkinter import ttk
-from test import support
 
-support.requires('gui')
+from test.test_tkinter.support import setUpGUIModule
+
+def setUpModule():
+    setUpGUIModule(__name__)
 
 class MiscTest(unittest.TestCase):
 
@@ -43,8 +45,5 @@
                 '^must specify a background color$',
                 root.tk_setPalette, highlightColor='blue')
 
-
-tests_gui = (MiscTest, )
-
 if __name__ == "__main__":
-    support.run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_text.py b/Lib/test/test_tkinter/test_tk/test_text.py
rename from Lib/tkinter/test/test_tkinter/test_text.py
rename to Lib/test/test_tkinter/test_tk/test_text.py
--- a/Lib/tkinter/test/test_tkinter/test_text.py
+++ b/Lib/test/test_tkinter/test_tk/test_text.py
@@ -1,9 +1,11 @@
 import unittest
 import tkinter
-from test.support import requires, run_unittest
 from tkinter.ttk import setup_master
 
-requires('gui')
+from test.test_tkinter.support import setUpGUIModule
+
+def setUpModule():
+    setUpGUIModule(__name__)
 
 class TextTest(unittest.TestCase):
 
@@ -43,8 +45,5 @@
         self.assertEqual(text.search('-test', '1.0', 'end'), '1.2')
         self.assertEqual(text.search('test', '1.0', 'end'), '1.3')
 
-
-tests_gui = (TextTest, )
-
 if __name__ == "__main__":
-    run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_variables.py b/Lib/test/test_tkinter/test_tk/test_variables.py
rename from Lib/tkinter/test/test_tkinter/test_variables.py
rename to Lib/test/test_tkinter/test_tk/test_variables.py
--- a/Lib/tkinter/test/test_tkinter/test_variables.py
+++ b/Lib/test/test_tkinter/test_tk/test_variables.py
@@ -2,6 +2,10 @@
 
 from tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tk
 
+from test.test_tkinter.support import setUpGUIModule
+
+def setUpModule():
+    setUpGUIModule(__name__)
 
 class Var(Variable):
 
@@ -177,10 +181,5 @@
             v.get()
 
 
-tests_gui = (TestVariable, TestStringVar, TestIntVar,
-             TestDoubleVar, TestBooleanVar)
-
-
 if __name__ == "__main__":
-    from test.support import run_unittest
-    run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_tkinter/test_widgets.py b/Lib/test/test_tkinter/test_tk/test_widgets.py
rename from Lib/tkinter/test/test_tkinter/test_widgets.py
rename to Lib/test/test_tkinter/test_tk/test_widgets.py
--- a/Lib/tkinter/test/test_tkinter/test_widgets.py
+++ b/Lib/test/test_tkinter/test_tk/test_widgets.py
@@ -3,17 +3,17 @@
 from tkinter import TclError
 import os
 import sys
-from test.support import requires
 
-from tkinter.test.support import (tcl_version, requires_tcl,
-                                  get_tk_patchlevel, widget_eq)
-from tkinter.test.widget_tests import (
+from test.test_tkinter.support import (tcl_version, requires_tcl,
+                                       get_tk_patchlevel, widget_eq,
+                                       setUpGUIModule)
+from test.test_tkinter.widget_tests import (
     add_standard_options, noconv, pixels_round,
     AbstractWidgetTest, StandardOptionsTests, IntegerSizeTests, PixelSizeTests,
-    setUpModule)
+    )
 
-requires('gui')
-
+def setUpModule():
+    setUpGUIModule(__name__)
 
 def float_round(x):
     return float(round(x))
@@ -1182,13 +1182,5 @@
         self.checkIntegerParam(widget, 'aspect', 250, 0, -300)
 
 
-tests_gui = (
-        ButtonTest, CanvasTest, CheckbuttonTest, EntryTest,
-        FrameTest, LabelFrameTest,LabelTest, ListboxTest,
-        MenubuttonTest, MenuTest, MessageTest, OptionMenuTest,
-        PanedWindowTest, RadiobuttonTest, ScaleTest, ScrollbarTest,
-        SpinboxTest, TextTest, ToplevelTest,
-)
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/tkinter/test/test_ttk/__init__.py b/Lib/test/test_tkinter/test_ttk/__init__.py
rename from Lib/tkinter/test/test_ttk/__init__.py
rename to Lib/test/test_tkinter/test_ttk/__init__.py
--- a/Lib/tkinter/test/test_ttk/__init__.py
+++ b/Lib/test/test_tkinter/test_ttk/__init__.py
@@ -0,0 +1,5 @@
+import os
+from test.support import load_package_tests
+
+def load_tests(*args):
+    return load_package_tests(os.path.dirname(__file__), *args)
diff --git a/Lib/test/test_tkinter/test_ttk/__main__.py b/Lib/test/test_tkinter/test_ttk/__main__.py
new file mode 100644
--- /dev/null
+++ b/Lib/test/test_tkinter/test_ttk/__main__.py
@@ -0,0 +1,4 @@
+from . import load_tests
+import unittest
+
+unittest.main()
diff --git a/Lib/tkinter/test/test_ttk/test_extensions.py b/Lib/test/test_tkinter/test_ttk/test_extensions.py
rename from Lib/tkinter/test/test_ttk/test_extensions.py
rename to Lib/test/test_tkinter/test_ttk/test_extensions.py
--- a/Lib/tkinter/test/test_ttk/test_extensions.py
+++ b/Lib/test/test_tkinter/test_ttk/test_extensions.py
@@ -2,11 +2,12 @@
 import unittest
 import tkinter
 from tkinter import ttk
-from test.support import requires, run_unittest
 
-import tkinter.test.support as support
+from test.test_tkinter import support
 
-requires('gui')
+def setUpModule():
+    support.setUpGUIModule(__name__)
+    support.check_ttk_availability()
 
 class LabeledScaleTest(unittest.TestCase):
 
@@ -278,7 +279,5 @@
         optmenu.destroy()
 
 
-tests_gui = (LabeledScaleTest, OptionMenuTest)
-
 if __name__ == "__main__":
-    run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_ttk/test_functions.py b/Lib/test/test_tkinter/test_ttk/test_functions.py
rename from Lib/tkinter/test/test_ttk/test_functions.py
rename to Lib/test/test_tkinter/test_ttk/test_functions.py
--- a/Lib/tkinter/test/test_ttk/test_functions.py
+++ b/Lib/test/test_tkinter/test_ttk/test_functions.py
@@ -468,8 +468,5 @@
         self.assertEqual(ttk.tclobjs_to_py({'text': 'some text'}),
             {'text': 'some text'})
 
-tests_nogui = (InternalFunctionsTest, TclObjsToPyTest)
-
 if __name__ == "__main__":
-    from test.support import run_unittest
-    run_unittest(*tests_nogui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_ttk/test_style.py b/Lib/test/test_tkinter/test_ttk/test_style.py
rename from Lib/tkinter/test/test_ttk/test_style.py
rename to Lib/test/test_tkinter/test_ttk/test_style.py
--- a/Lib/tkinter/test/test_ttk/test_style.py
+++ b/Lib/test/test_tkinter/test_ttk/test_style.py
@@ -1,11 +1,12 @@
 import unittest
 import tkinter
 from tkinter import ttk
-from test.support import requires, run_unittest
 
-import tkinter.test.support as support
+from test.test_tkinter import support
 
-requires('gui')
+def setUpModule():
+    support.setUpGUIModule(__name__)
+    support.check_ttk_availability()
 
 class StyleTest(unittest.TestCase):
 
@@ -86,7 +87,5 @@
         self.style.theme_use(curr_theme)
 
 
-tests_gui = (StyleTest, )
-
 if __name__ == "__main__":
-    run_unittest(*tests_gui)
+    unittest.main()
diff --git a/Lib/tkinter/test/test_ttk/test_widgets.py b/Lib/test/test_tkinter/test_ttk/test_widgets.py
rename from Lib/tkinter/test/test_ttk/test_widgets.py
rename to Lib/test/test_tkinter/test_ttk/test_widgets.py
--- a/Lib/tkinter/test/test_ttk/test_widgets.py
+++ b/Lib/test/test_tkinter/test_ttk/test_widgets.py
@@ -1,18 +1,18 @@
 import unittest
 import tkinter
 from tkinter import ttk
-from test.support import requires
 import sys
 
-import tkinter.test.support as support
-from tkinter.test.test_ttk.test_functions import MockTclObj
-from tkinter.test.support import tcl_version, get_tk_patchlevel
-from tkinter.test.widget_tests import (add_standard_options, noconv,
+from test.test_tkinter import support
+from test.test_tkinter.test_ttk.test_functions import MockTclObj
+from test.test_tkinter.support import tcl_version, get_tk_patchlevel
+from test.test_tkinter.widget_tests import (add_standard_options, noconv,
     AbstractWidgetTest, StandardOptionsTests, IntegerSizeTests, PixelSizeTests,
-    setUpModule)
+    )
 
-requires('gui')
-
+def setUpModule():
+    support.setUpGUIModule(__name__)
+    support.check_ttk_availability()
 
 class StandardTtkOptionsTests(StandardOptionsTests):
 
@@ -1626,13 +1626,5 @@
     def _create(self, **kwargs):
         return ttk.Sizegrip(self.root, **kwargs)
 
-tests_gui = (
-        ButtonTest, CheckbuttonTest, ComboboxTest, EntryTest,
-        FrameTest, LabelFrameTest, LabelTest, MenubuttonTest,
-        NotebookTest, PanedWindowTest, ProgressbarTest,
-        RadiobuttonTest, ScaleTest, ScrollbarTest, SeparatorTest,
-        SizegripTest, TreeviewTest, WidgetTest,
-        )
-
 if __name__ == "__main__":
     unittest.main()
diff --git a/Lib/tkinter/test/widget_tests.py b/Lib/test/test_tkinter/widget_tests.py
rename from Lib/tkinter/test/widget_tests.py
rename to Lib/test/test_tkinter/widget_tests.py
--- a/Lib/tkinter/test/widget_tests.py
+++ b/Lib/test/test_tkinter/widget_tests.py
@@ -4,8 +4,9 @@
 import sys
 import tkinter
 from tkinter.ttk import setup_master, Scale
-from tkinter.test.support import (tcl_version, requires_tcl, get_tk_patchlevel,
-                                  pixels_conv, tcl_obj_eq)
+from test.test_tkinter.support import (tcl_version, requires_tcl,
+                                       get_tk_patchlevel, pixels_conv,
+                                       tcl_obj_eq)
 import test.support
 
 
@@ -521,8 +522,3 @@
                     setattr(cls, methodname, test)
         return cls
     return decorator
-
-def setUpModule():
-    if test.support.verbose:
-        tcl = tkinter.Tcl()
-        print('patchlevel =', tcl.call('info', 'patchlevel'))
diff --git a/Lib/test/test_ttk_guionly.py b/Lib/test/test_ttk_guionly.py
deleted file mode 100644
--- a/Lib/test/test_ttk_guionly.py
+++ /dev/null
@@ -1,33 +0,0 @@
-import os
-import unittest
-from test import support
-
-# Skip this test if _tkinter wasn't built.
-support.import_module('_tkinter')
-
-# Make sure tkinter._fix runs to set up the environment
-support.import_fresh_module('tkinter')
-
-# Skip test if tk cannot be initialized.
-support.requires('gui')
-
-from _tkinter import TclError
-from tkinter import ttk
-from tkinter.test import runtktests
-from tkinter.test.support import get_tk_root
-
-try:
-    ttk.Button()
-except TclError as msg:
-    # assuming ttk is not available
-    raise unittest.SkipTest("ttk not available: %s" % msg)
-
-def test_main():
-    try:
-        support.run_unittest(
-                *runtktests.get_tests(text=False, packages=['test_ttk']))
-    finally:
-        get_tk_root().destroy()
-
-if __name__ == '__main__':
-    test_main()
diff --git a/Lib/test/test_ttk_textonly.py b/Lib/test/test_ttk_textonly.py
deleted file mode 100644
--- a/Lib/test/test_ttk_textonly.py
+++ /dev/null
@@ -1,17 +0,0 @@
-import os
-from test import support
-
-# Skip this test if _tkinter does not exist.
-support.import_module('_tkinter')
-
-# Make sure tkinter._fix runs to set up the environment
-support.import_fresh_module('tkinter')
-
-from tkinter.test import runtktests
-
-def test_main():
-    support.run_unittest(
-            *runtktests.get_tests(gui=False, packages=['test_ttk']))
-
-if __name__ == '__main__':
-    test_main()
diff --git a/Lib/tkinter/test/runtktests.py b/Lib/tkinter/test/runtktests.py
deleted file mode 100644
--- a/Lib/tkinter/test/runtktests.py
+++ /dev/null
@@ -1,71 +0,0 @@
-"""
-Use this module to get and run all tk tests.
-
-tkinter tests should live in a package inside the directory where this file
-lives, like test_tkinter.
-Extensions also should live in packages following the same rule as above.
-"""
-
-import os
-import sys
-import unittest
-import importlib
-import test.support
-
-this_dir_path = os.path.abspath(os.path.dirname(__file__))
-
-def is_package(path):
-    for name in os.listdir(path):
-        if name in ('__init__.py', '__init__.pyc', '__init.pyo'):
-            return True
-    return False
-
-def get_tests_modules(basepath=this_dir_path, gui=True, packages=None):
-    """This will import and yield modules whose names start with test_
-    and are inside packages found in the path starting at basepath.
-
-    If packages is specified it should contain package names that
-    want their tests collected.
-    """
-    py_ext = '.py'
-
-    for dirpath, dirnames, filenames in os.walk(basepath):
-        for dirname in list(dirnames):
-            if dirname[0] == '.':
-                dirnames.remove(dirname)
-
-        if is_package(dirpath) and filenames:
-            pkg_name = dirpath[len(basepath) + len(os.sep):].replace('/', '.')
-            if packages and pkg_name not in packages:
-                continue
-
-            filenames = filter(
-                    lambda x: x.startswith('test_') and x.endswith(py_ext),
-                    filenames)
-
-            for name in filenames:
-                try:
-                    yield importlib.import_module(
-                        ".%s.%s" % (pkg_name, name[:-len(py_ext)]),
-                        "tkinter.test")
-                except test.support.ResourceDenied:
-                    if gui:
-                        raise
-
-def get_tests(text=True, gui=True, packages=None):
-    """Yield all the tests in the modules found by get_tests_modules.
-
-    If nogui is True, only tests that do not require a GUI will be
-    returned."""
-    attrs = []
-    if text:
-        attrs.append('tests_nogui')
-    if gui:
-        attrs.append('tests_gui')
-    for module in get_tests_modules(gui=gui, packages=packages):
-        for attr in attrs:
-            for test in getattr(module, attr, ()):
-                yield test
-
-if __name__ == "__main__":
-    test.support.run_unittest(*get_tests())