In IDLE, sys.stdout.write and sys.stderr can write any pickleable object

Lib/idlelib/run.py

 import sys
 import io
 import linecache
 import time
 import socket
 import traceback
 import _thread as thread
 import threading
 import queue
 import tkinter
@@ skipping 258 matching lines @@
         return getattr(self.rpc, name)
 
     def __setattr__(self, name, value):
         return setattr(self.rpc, name, value)
 
     def write(self, s):
         if not isinstance(s, str):
             raise TypeError('must be str, not ' + type(s).__name__)
         return self.rpc.write(s)
 
+    def readline(self):
+        return self.rpc.readline()
+
+    def isatty(self):
+        return self.rpc.isatty()
+
 class MyHandler(rpc.RPCHandler):
 
     def handle(self):
         """Override base method"""
         executive = Executive(self)
         self.register("exec", executive)
         sys.stdin = self.console = _RPCFile(self.get_remote_proxy("stdin"))
         sys.stdout = _RPCFile(self.get_remote_proxy("stdout"))
         sys.stderr = _RPCFile(self.get_remote_proxy("stderr"))
         sys.displayhook = rpc.displayhook
@@ skipping 76 matching lines @@
             return None
         flist = None
         if flist_oid is not None:
             flist = self.rpchandler.get_remote_proxy(flist_oid)
         while tb and tb.tb_frame.f_globals["__name__"] in ["rpc", "run"]:
             tb = tb.tb_next
         sys.last_type = typ
         sys.last_value = val
         item = StackViewer.StackTreeItem(flist, tb)
         return RemoteObjectBrowser.remote_object_tree_item(item)