Simplify various spots where: str() is called on something
that already is a string or the existence of the str class
is checked or a check is done for str twice. These all stem
from the initial unicode->str replacement.
diff --git a/Lib/xml/dom/minicompat.py b/Lib/xml/dom/minicompat.py
index e2a2bca..c0a797e 100644
--- a/Lib/xml/dom/minicompat.py
+++ b/Lib/xml/dom/minicompat.py
@@ -40,12 +40,7 @@
 
 import xml.dom
 
-try:
-    str
-except NameError:
-    StringTypes = type(''),
-else:
-    StringTypes = type(''), type(str(''))
+StringTypes = (str,)
 
 
 class NodeList(list):