Use readline/raw_input() in pydoc.Helper.interact if available and self.input
is sys.stdin. Based on a patch (#726204) by Dmitry Vasiliev and a comment from
Guido in an older patch (#549901).
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index c02c140..12ae277 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -1618,16 +1618,24 @@
     def interact(self):
         self.output.write('\n')
         while True:
-            self.output.write('help> ')
-            self.output.flush()
             try:
-                request = self.input.readline()
+                request = self.getline('help> ')
                 if not request: break
-            except KeyboardInterrupt: break
+            except (KeyboardInterrupt, EOFError):
+                break
             request = strip(replace(request, '"', '', "'", ''))
             if lower(request) in ['q', 'quit']: break
             self.help(request)
 
+    def getline(self, prompt):
+        """Read one line, using raw_input when available."""
+        if self.input is sys.stdin:
+            return raw_input(prompt)
+        else:
+            self.output.write(prompt)
+            self.output.flush()
+            return self.input.readline()
+
     def help(self, request):
         if type(request) is type(''):
             if request == 'help': self.intro()