Replace backticks with repr() or "%r"

From SF patch #852334.
diff --git a/Lib/pprint.py b/Lib/pprint.py
index d938122..716f35d 100644
--- a/Lib/pprint.py
+++ b/Lib/pprint.py
@@ -212,7 +212,7 @@
     typ = _type(object)
     if typ is str:
         if 'locale' not in _sys.modules:
-            return `object`, True, False
+            return repr(object), True, False
         if "'" in object and '"' not in object:
             closure = '"'
             quotes = {'"': '\\"'}
@@ -226,7 +226,7 @@
             if char.isalpha():
                 write(char)
             else:
-                write(qget(char, `char`[1:-1]))
+                write(qget(char, repr(char)[1:-1]))
         return ("%s%s%s" % (closure, sio.getvalue(), closure)), True, False
 
     r = typ.__repr__
@@ -288,7 +288,7 @@
         del context[objid]
         return format % _commajoin(components), readable, recursive
 
-    rep = `object`
+    rep = repr(object)
     return rep, (rep and not rep.startswith('<')), False