bpo-33855: Still more edits and minimal tests for IDLE (GH-7784)

Part 3 of 3, continuing PR #7689. This covers 14 idlelib modules and their tests,
rpc to zoomheight except for run (already done) and tooltip (being done separately).

Lib/idlelib/idle_test/test_textview.py

@@ -1,17 +1,15 @@
-'''Test idlelib.textview.
+"""Test textview, coverage 100%.
 
 Since all methods and functions create (or destroy) a ViewWindow, which
 is a widget containing a widget, etcetera, all tests must be gui tests.
 Using mock Text would not change this.  Other mocks are used to retrieve
 information about calls.
-
-Coverage: 100%.
-'''
+"""
 from idlelib import textview as tv
+import unittest
 from test.support import requires
 requires('gui')
 
-import unittest
 import os
 from tkinter import Tk
 from tkinter.ttk import Button
@@ -109,7 +107,7 @@ class ViewFunctionTest(unittest.TestCase):
         view = tv.view_text(root, 'Title', 'test text', modal=False)
         self.assertIsInstance(view, tv.ViewWindow)
         self.assertIsInstance(view.viewframe, tv.ViewFrame)
-        view.ok()
+        view.viewframe.ok()
 
     def test_view_file(self):
         view = tv.view_file(root, 'Title', __file__, 'ascii', modal=False)