Merge pull request #4120 from minrk/input-py2

support `input` in Python 2 kernels

IPython/kernel/tests/test_kernel.py

@@ -1,204 +1,252
 """test the IPython Kernel"""
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2013  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 
 import os
 import shutil
 import sys
 import tempfile
 
 from contextlib import contextmanager
 from subprocess import PIPE
 
 import nose.tools as nt
 
 from IPython.kernel import KernelManager
 from IPython.kernel.tests.test_message_spec import execute, flush_channels
 from IPython.testing import decorators as dec
-from IPython.utils import path
+from IPython.utils import path, py3compat
 
 #-------------------------------------------------------------------------------
 # Tests
 #-------------------------------------------------------------------------------
 IPYTHONDIR = None
 save_env = None
 save_get_ipython_dir = None
 
+STARTUP_TIMEOUT = 60
+TIMEOUT = 15
+
 def setup():
     """setup temporary IPYTHONDIR for tests"""
     global IPYTHONDIR
     global save_env
     global save_get_ipython_dir
     
     IPYTHONDIR = tempfile.mkdtemp()
 
     save_env = os.environ.copy()
     os.environ["IPYTHONDIR"] = IPYTHONDIR
 
     save_get_ipython_dir = path.get_ipython_dir
     path.get_ipython_dir = lambda : IPYTHONDIR
 
 
 def teardown():
     path.get_ipython_dir = save_get_ipython_dir
     os.environ = save_env
     
     try:
         shutil.rmtree(IPYTHONDIR)
     except (OSError, IOError):
         # no such file
         pass
 
 
 @contextmanager
 def new_kernel():
     """start a kernel in a subprocess, and wait for it to be ready
     
     Returns
     -------
     kernel_manager: connected KernelManager instance
     """
     KM = KernelManager()
 
     KM.start_kernel(stdout=PIPE, stderr=PIPE)
     KC = KM.client()
     KC.start_channels()
     
     # wait for kernel to be ready
     KC.shell_channel.execute("import sys")
-    KC.shell_channel.get_msg(block=True, timeout=5)
+    KC.shell_channel.get_msg(block=True, timeout=STARTUP_TIMEOUT)
     flush_channels(KC)
     try:
         yield KC
     finally:
         KC.stop_channels()
         KM.shutdown_kernel()
 
 
 def assemble_output(iopub):
     """assemble stdout/err from an execution"""
     stdout = ''
     stderr = ''
     while True:
         msg = iopub.get_msg(block=True, timeout=1)
         msg_type = msg['msg_type']
         content = msg['content']
         if msg_type == 'status' and content['execution_state'] == 'idle':
             # idle message signals end of output
             break
         elif msg['msg_type'] == 'stream':
             if content['name'] == 'stdout':
                 stdout = stdout + content['data']
             elif content['name'] == 'stderr':
                 stderr = stderr + content['data']
             else:
                 raise KeyError("bad stream: %r" % content['name'])
         else:
             # other output, ignored
             pass
     return stdout, stderr
 
 
 def _check_mp_mode(kc, expected=False, stream="stdout"):
     execute(kc=kc, code="import sys")
     flush_channels(kc)
     msg_id, content = execute(kc=kc, code="print (sys.%s._check_mp_mode())" % stream)
     stdout, stderr = assemble_output(kc.iopub_channel)
     nt.assert_equal(eval(stdout.strip()), expected)
 
 
+# printing tests
+
 def test_simple_print():
     """simple print statement in kernel"""
     with new_kernel() as kc:
         iopub = kc.iopub_channel
         msg_id, content = execute(kc=kc, code="print ('hi')")
         stdout, stderr = assemble_output(iopub)
         nt.assert_equal(stdout, 'hi\n')
         nt.assert_equal(stderr, '')
         _check_mp_mode(kc, expected=False)
-    print ('hello')
 
 
 @dec.knownfailureif(sys.platform == 'win32', "subprocess prints fail on Windows")
 def test_subprocess_print():
     """printing from forked mp.Process"""
     with new_kernel() as kc:
         iopub = kc.iopub_channel
         
         _check_mp_mode(kc, expected=False)
         flush_channels(kc)
         np = 5
         code = '\n'.join([
             "from __future__ import print_function",
             "import multiprocessing as mp",
             "pool = [mp.Process(target=print, args=('hello', i,)) for i in range(%i)]" % np,
             "for p in pool: p.start()",
             "for p in pool: p.join()"
         ])
         
         expected = '\n'.join([
             "hello %s" % i for i in range(np)
         ]) + '\n'
         
         msg_id, content = execute(kc=kc, code=code)
         stdout, stderr = assemble_output(iopub)
         nt.assert_equal(stdout.count("hello"), np, stdout)
         for n in range(np):
             nt.assert_equal(stdout.count(str(n)), 1, stdout)
         nt.assert_equal(stderr, '')
         _check_mp_mode(kc, expected=False)
         _check_mp_mode(kc, expected=False, stream="stderr")
 
 
 def test_subprocess_noprint():
     """mp.Process without print doesn't trigger iostream mp_mode"""
     with new_kernel() as kc:
         iopub = kc.iopub_channel
         
         np = 5
         code = '\n'.join([
             "import multiprocessing as mp",
             "pool = [mp.Process(target=range, args=(i,)) for i in range(%i)]" % np,
             "for p in pool: p.start()",
             "for p in pool: p.join()"
         ])
         
         msg_id, content = execute(kc=kc, code=code)
         stdout, stderr = assemble_output(iopub)
         nt.assert_equal(stdout, '')
         nt.assert_equal(stderr, '')
 
         _check_mp_mode(kc, expected=False)
         _check_mp_mode(kc, expected=False, stream="stderr")
 
 
 @dec.knownfailureif(sys.platform == 'win32', "subprocess prints fail on Windows")
 def test_subprocess_error():
     """error in mp.Process doesn't crash"""
     with new_kernel() as kc:
         iopub = kc.iopub_channel
         
         code = '\n'.join([
             "import multiprocessing as mp",
             "p = mp.Process(target=int, args=('hi',))",
             "p.start()",
             "p.join()",
         ])
         
         msg_id, content = execute(kc=kc, code=code)
         stdout, stderr = assemble_output(iopub)
         nt.assert_equal(stdout, '')
         nt.assert_true("ValueError" in stderr, stderr)
 
         _check_mp_mode(kc, expected=False)
         _check_mp_mode(kc, expected=False, stream="stderr")
 
+
+# raw_input tests
+
+def test_raw_input():
+    """test [raw_]input"""
+    with new_kernel() as kc:
+        iopub = kc.iopub_channel
+        
+        input_f = "input" if py3compat.PY3 else "raw_input"
+        theprompt = "prompt> "
+        code = 'print({input_f}("{theprompt}"))'.format(**locals())
+        msg_id = kc.execute(code, allow_stdin=True)
+        msg = kc.get_stdin_msg(block=True, timeout=TIMEOUT)
+        nt.assert_equal(msg['header']['msg_type'], u'input_request')
+        content = msg['content']
+        nt.assert_equal(content['prompt'], theprompt)
+        text = "some text"
+        kc.input(text)
+        reply = kc.get_shell_msg(block=True, timeout=TIMEOUT)
+        nt.assert_equal(reply['content']['status'], 'ok')
+        stdout, stderr = assemble_output(iopub)
+        nt.assert_equal(stdout, text + "\n")
+
+
[e-mail](py3compat.PY3)
+def test_eval_input():
+    """test input() on Python 2"""
+    with new_kernel() as kc:
+        iopub = kc.iopub_channel
+        
+        input_f = "input" if py3compat.PY3 else "raw_input"
+        theprompt = "prompt> "
+        code = 'print(input("{theprompt}"))'.format(**locals())
+        msg_id = kc.execute(code, allow_stdin=True)
+        msg = kc.get_stdin_msg(block=True, timeout=TIMEOUT)
+        nt.assert_equal(msg['header']['msg_type'], u'input_request')
+        content = msg['content']
+        nt.assert_equal(content['prompt'], theprompt)
+        kc.input("1+1")
+        reply = kc.get_shell_msg(block=True, timeout=TIMEOUT)
+        nt.assert_equal(reply['content']['status'], 'ok')
+        stdout, stderr = assemble_output(iopub)
+        nt.assert_equal(stdout, "2\n")
+

IPython/kernel/zmq/ipkernel.py

@@ -1,806 +1,811
 #!/usr/bin/env python
 """A simple interactive kernel that talks to a frontend over 0MQ.
 
 Things to do:
 
 * Implement `set_parent` logic. Right before doing exec, the Kernel should
   call set_parent on all the PUB objects with the message about to be executed.
 * Implement random port and security key logic.
 * Implement control messages.
 * Implement event loop and poll version.
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Standard library imports
 import __builtin__
 import sys
 import time
 import traceback
 import logging
 import uuid
 
 from datetime import datetime
 from signal import (
         signal, default_int_handler, SIGINT
 )
 
 # System library imports
 import zmq
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 # Local imports
 from IPython.config.configurable import Configurable
 from IPython.core.error import StdinNotImplementedError
 from IPython.core import release
 from IPython.utils import py3compat
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import (
     Any, Instance, Float, Dict, List, Set, Integer, Unicode,
     Type
 )
 
 from serialize import serialize_object, unpack_apply_message
 from session import Session
 from zmqshell import ZMQInteractiveShell
 
 
 #-----------------------------------------------------------------------------
 # Main kernel class
 #-----------------------------------------------------------------------------
 
 protocol_version = list(release.kernel_protocol_version_info)
 ipython_version = list(release.version_info)
 language_version = list(sys.version_info[:3])
 
 
 class Kernel(Configurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface
     #---------------------------------------------------------------------------
 
     # attribute to override with a GUI
     eventloop = Any(None)
     def _eventloop_changed(self, name, old, new):
         """schedule call to eventloop from IOLoop"""
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, self.enter_eventloop)
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     shell_class = Type(ZMQInteractiveShell)
 
     session = Instance(Session)
     profile_dir = Instance('IPython.core.profiledir.ProfileDir')
     shell_streams = List()
     control_stream = Instance(ZMQStream)
     iopub_socket = Instance(zmq.Socket)
     stdin_socket = Instance(zmq.Socket)
     log = Instance(logging.Logger)
     
     user_module = Any()
     def _user_module_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_module = new
     
     user_ns = Dict(default_value=None)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     # identities:
     int_id = Integer(-1)
     ident = Unicode()
 
     def _ident_default(self):
         return unicode(uuid.uuid4())
 
 
     # Private interface
     
     # Time to sleep after flushing the stdout/err buffers in each execute
     # cycle.  While this introduces a hard limit on the minimal latency of the
     # execute cycle, it helps prevent output synchronization problems for
     # clients.
     # Units are in seconds.  The minimum zmq latency on local host is probably
     # ~150 microseconds, set this to 500us for now.  We may need to increase it
     # a little if it's not enough after more interactive testing.
     _execute_sleep = Float(0.0005, config=True)
 
     # Frequency of the kernel's event loop.
     # Units are in seconds, kernel subclasses for GUI toolkits may need to
     # adapt to milliseconds.
     _poll_interval = Float(0.05, config=True)
 
     # If the shutdown was requested over the network, we leave here the
     # necessary reply message so it can be sent by our registered atexit
     # handler.  This ensures that the reply is only sent to clients truly at
     # the end of our shutdown process (which happens after the underlying
     # IPython shell's own shutdown).
     _shutdown_message = None
 
     # This is a dict of port number that the kernel is listening on. It is set
     # by record_ports and used by connect_request.
     _recorded_ports = Dict()
 
     # A reference to the Python builtin 'raw_input' function.
     # (i.e., __builtin__.raw_input for Python 2.7, builtins.input for Python 3)
     _sys_raw_input = Any()
+    _sys_eval_input = Any()
 
     # set of aborted msg_ids
     aborted = Set()
 
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
 
         # Initialize the InteractiveShell subclass
         self.shell = self.shell_class.instance(parent=self,
             profile_dir = self.profile_dir,
             user_module = self.user_module,
             user_ns     = self.user_ns,
         )
         self.shell.displayhook.session = self.session
         self.shell.displayhook.pub_socket = self.iopub_socket
         self.shell.displayhook.topic = self._topic('pyout')
         self.shell.display_pub.session = self.session
         self.shell.display_pub.pub_socket = self.iopub_socket
         self.shell.data_pub.session = self.session
         self.shell.data_pub.pub_socket = self.iopub_socket
 
         # TMP - hack while developing
         self.shell._reply_content = None
 
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request',
                       'object_info_request', 'history_request',
                       'kernel_info_request',
                       'connect_request', 'shutdown_request',
                       'apply_request',
                     ]
         self.shell_handlers = {}
         for msg_type in msg_types:
             self.shell_handlers[msg_type] = getattr(self, msg_type)
         
         control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
         self.control_handlers = {}
         for msg_type in control_msg_types:
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
     def dispatch_control(self, msg):
         """dispatch control requests"""
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Control Message", exc_info=True)
             return
 
         self.log.debug("Control received: %s", msg)
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = header['msg_type']
 
         handler = self.control_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN CONTROL MESSAGE TYPE: %r", msg_type)
         else:
             try:
                 handler(self.control_stream, idents, msg)
             except Exception:
                 self.log.error("Exception in control handler:", exc_info=True)
     
     def dispatch_shell(self, stream, msg):
         """dispatch shell requests"""
         # flush control requests first
         if self.control_stream:
             self.control_stream.flush()
         
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Message", exc_info=True)
             return
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = msg['header']['msg_type']
         
         # Print some info about this message and leave a '--->' marker, so it's
         # easier to trace visually the message chain when debugging.  Each
         # handler prints its message at the end.
         self.log.debug('\n*** MESSAGE TYPE:%s***', msg_type)
         self.log.debug('   Content: %s\n   --->\n   ', msg['content'])
 
         if msg_id in self.aborted:
             self.aborted.remove(msg_id)
             # is it safe to assume a msg_id will not be resubmitted?
             reply_type = msg_type.split('_')[0] + '_reply'
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             return
         
         handler = self.shell_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN MESSAGE TYPE: %r", msg_type)
         else:
             # ensure default_int_handler during handler call
             sig = signal(SIGINT, default_int_handler)
             try:
                 handler(stream, idents, msg)
             except Exception:
                 self.log.error("Exception in message handler:", exc_info=True)
             finally:
                 signal(SIGINT, sig)
     
     def enter_eventloop(self):
         """enter eventloop"""
         self.log.info("entering eventloop")
         # restore default_int_handler
         signal(SIGINT, default_int_handler)
         while self.eventloop is not None:
             try:
                 self.eventloop(self)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 self.log.error("KeyboardInterrupt caught in kernel")
                 continue
             else:
                 # eventloop exited cleanly, this means we should stop (right?)
                 self.eventloop = None
                 break
         self.log.info("exiting eventloop")
 
     def start(self):
         """register dispatchers for streams"""
         self.shell.exit_now = False
         if self.control_stream:
             self.control_stream.on_recv(self.dispatch_control, copy=False)
 
         def make_dispatcher(stream):
             def dispatcher(msg):
                 return self.dispatch_shell(stream, msg)
             return dispatcher
 
         for s in self.shell_streams:
             s.on_recv(make_dispatcher(s), copy=False)
 
         # publish idle status
         self._publish_status('starting')
     
     def do_one_iteration(self):
         """step eventloop just once"""
         if self.control_stream:
             self.control_stream.flush()
         for stream in self.shell_streams:
             # handle at most one request per iteration
             stream.flush(zmq.POLLIN, 1)
             stream.flush(zmq.POLLOUT)
 
 
     def record_ports(self, ports):
         """Record the ports that this kernel is using.
 
         The creator of the Kernel instance must call this methods if they
         want the :meth:`connect_request` method to return the port numbers.
         """
         self._recorded_ports = ports
 
     #---------------------------------------------------------------------------
     # Kernel request handlers
     #---------------------------------------------------------------------------
     
     def _make_metadata(self, other=None):
         """init metadata dict, for execute/apply_reply"""
         new_md = {
             'dependencies_met' : True,
             'engine' : self.ident,
             'started': datetime.now(),
         }
         if other:
             new_md.update(other)
         return new_md
     
     def _publish_pyin(self, code, parent, execution_count):
         """Publish the code request on the pyin stream."""
 
         self.session.send(self.iopub_socket, u'pyin',
                             {u'code':code, u'execution_count': execution_count},
                             parent=parent, ident=self._topic('pyin')
         )
     
     def _publish_status(self, status, parent=None):
         """send status (busy/idle) on IOPub"""
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state': status},
                           parent=parent,
                           ident=self._topic('status'),
                           )
         
 
     def execute_request(self, stream, ident, parent):
         """handle an execute_request"""
         
         self._publish_status(u'busy', parent)
         
         try:
             content = parent[u'content']
             code = content[u'code']
             silent = content[u'silent']
             store_history = content.get(u'store_history', not silent)
         except:
             self.log.error("Got bad msg: ")
             self.log.error("%s", parent)
             return
         
         md = self._make_metadata(parent['metadata'])
 
         shell = self.shell # we'll need this a lot here
 
         # Replace raw_input. Note that is not sufficient to replace
         # raw_input in the user namespace.
         if content.get('allow_stdin', False):
             raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
+            input = lambda prompt='': eval(raw_input(prompt))
         else:
-            raw_input = lambda prompt='' : self._no_raw_input()
+            raw_input = input = lambda prompt='' : self._no_raw_input()
 
         if py3compat.PY3:
             self._sys_raw_input = __builtin__.input
             __builtin__.input = raw_input
         else:
             self._sys_raw_input = __builtin__.raw_input
+            self._sys_eval_input = __builtin__.input
             __builtin__.raw_input = raw_input
+            __builtin__.input = input
 
         # Set the parent message of the display hook and out streams.
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
         try:
             sys.stdout.set_parent(parent)
         except AttributeError:
             pass
         try:
             sys.stderr.set_parent(parent)
         except AttributeError:
             pass
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
         if not silent:
             self._publish_pyin(code, parent, shell.execution_count)
 
         reply_content = {}
         try:
             # FIXME: the shell calls the exception handler itself.
             shell.run_cell(code, store_history=store_history, silent=silent)
         except:
             status = u'error'
             # FIXME: this code right now isn't being used yet by default,
             # because the run_cell() call above directly fires off exception
             # reporting.  This code, therefore, is only active in the scenario
             # where runlines itself has an unhandled exception.  We need to
             # uniformize this, for all exception construction to come from a
             # single location in the codbase.
             etype, evalue, tb = sys.exc_info()
             tb_list = traceback.format_exception(etype, evalue, tb)
             reply_content.update(shell._showtraceback(etype, evalue, tb_list))
         else:
             status = u'ok'
         finally:
             # Restore raw_input.
              if py3compat.PY3:
                  __builtin__.input = self._sys_raw_input
              else:
                  __builtin__.raw_input = self._sys_raw_input
+                 __builtin__.input = self._sys_eval_input
 
         reply_content[u'status'] = status
 
         # Return the execution counter so clients can display prompts
         reply_content['execution_count'] = shell.execution_count - 1
 
         # FIXME - fish exception info out of shell, possibly left there by
         # runlines.  We'll need to clean up this logic later.
         if shell._reply_content is not None:
             reply_content.update(shell._reply_content)
             e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='execute')
             reply_content['engine_info'] = e_info
             # reset after use
             shell._reply_content = None
         
         if 'traceback' in reply_content:
             self.log.info("Exception in execute request:\n%s", '\n'.join(reply_content['traceback']))
         
 
         # At this point, we can tell whether the main code execution succeeded
         # or not.  If it did, we proceed to evaluate user_variables/expressions
         if reply_content['status'] == 'ok':
             reply_content[u'user_variables'] = \
                          shell.user_variables(content.get(u'user_variables', []))
             reply_content[u'user_expressions'] = \
                          shell.user_expressions(content.get(u'user_expressions', {}))
         else:
             # If there was an error, don't even try to compute variables or
             # expressions
             reply_content[u'user_variables'] = {}
             reply_content[u'user_expressions'] = {}
 
         # Payloads should be retrieved regardless of outcome, so we can both
         # recover partial output (that could have been generated early in a
         # block, before an error) and clear the payload system always.
         reply_content[u'payload'] = shell.payload_manager.read_payload()
         # Be agressive about clearing the payload because we don't want
         # it to sit in memory until the next execute_request comes in.
         shell.payload_manager.clear_payload()
 
         # Flush output before sending the reply.
         sys.stdout.flush()
         sys.stderr.flush()
         # FIXME: on rare occasions, the flush doesn't seem to make it to the
         # clients... This seems to mitigate the problem, but we definitely need
         # to better understand what's going on.
         if self._execute_sleep:
             time.sleep(self._execute_sleep)
 
         # Send the reply.
         reply_content = json_clean(reply_content)
         
         md['status'] = reply_content['status']
         if reply_content['status'] == 'error' and \
                         reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
 
         reply_msg = self.session.send(stream, u'execute_reply',
                                       reply_content, parent, metadata=md,
                                       ident=ident)
         
         self.log.debug("%s", reply_msg)
 
         if not silent and reply_msg['content']['status'] == u'error':
             self._abort_queues()
 
         self._publish_status(u'idle', parent)
 
     def complete_request(self, stream, ident, parent):
         txt, matches = self._complete(parent)
         matches = {'matches' : matches,
                    'matched_text' : txt,
                    'status' : 'ok'}
         matches = json_clean(matches)
         completion_msg = self.session.send(stream, 'complete_reply',
                                            matches, parent, ident)
         self.log.debug("%s", completion_msg)
 
     def object_info_request(self, stream, ident, parent):
         content = parent['content']
         object_info = self.shell.object_inspect(content['oname'],
                         detail_level = content.get('detail_level', 0)
         )
         # Before we send this object over, we scrub it for JSON usage
         oinfo = json_clean(object_info)
         msg = self.session.send(stream, 'object_info_reply',
                                 oinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def history_request(self, stream, ident, parent):
         # We need to pull these out, as passing **kwargs doesn't work with
         # unicode keys before Python 2.6.5.
         hist_access_type = parent['content']['hist_access_type']
         raw = parent['content']['raw']
         output = parent['content']['output']
         if hist_access_type == 'tail':
             n = parent['content']['n']
             hist = self.shell.history_manager.get_tail(n, raw=raw, output=output,
                                                             include_latest=True)
 
         elif hist_access_type == 'range':
             session = parent['content']['session']
             start = parent['content']['start']
             stop = parent['content']['stop']
             hist = self.shell.history_manager.get_range(session, start, stop,
                                                         raw=raw, output=output)
 
         elif hist_access_type == 'search':
             n = parent['content'].get('n')
             unique = parent['content'].get('unique', False)
             pattern = parent['content']['pattern']
             hist = self.shell.history_manager.search(
                 pattern, raw=raw, output=output, n=n, unique=unique)
 
         else:
             hist = []
         hist = list(hist)
         content = {'history' : hist}
         content = json_clean(content)
         msg = self.session.send(stream, 'history_reply',
                                 content, parent, ident)
         self.log.debug("Sending history reply with %i entries", len(hist))
 
     def connect_request(self, stream, ident, parent):
         if self._recorded_ports is not None:
             content = self._recorded_ports.copy()
         else:
             content = {}
         msg = self.session.send(stream, 'connect_reply',
                                 content, parent, ident)
         self.log.debug("%s", msg)
 
     def kernel_info_request(self, stream, ident, parent):
         vinfo = {
             'protocol_version': protocol_version,
             'ipython_version': ipython_version,
             'language_version': language_version,
             'language': 'python',
         }
         msg = self.session.send(stream, 'kernel_info_reply',
                                 vinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def shutdown_request(self, stream, ident, parent):
         self.shell.exit_now = True
         content = dict(status='ok')
         content.update(parent['content'])
         self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)
         # same content, but different msg_id for broadcasting on IOPub
         self._shutdown_message = self.session.msg(u'shutdown_reply',
                                                   content, parent
         )
 
         self._at_shutdown()
         # call sys.exit after a short delay
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, loop.stop)
 
     #---------------------------------------------------------------------------
     # Engine methods
     #---------------------------------------------------------------------------
 
     def apply_request(self, stream, ident, parent):
         try:
             content = parent[u'content']
             bufs = parent[u'buffers']
             msg_id = parent['header']['msg_id']
         except:
             self.log.error("Got bad msg: %s", parent, exc_info=True)
             return
 
         self._publish_status(u'busy', parent)
 
         # Set the parent message of the display hook and out streams.
         shell = self.shell
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
         try:
             sys.stdout.set_parent(parent)
         except AttributeError:
             pass
         try:
             sys.stderr.set_parent(parent)
         except AttributeError:
             pass
 
         # pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         # self.iopub_socket.send(pyin_msg)
         # self.session.send(self.iopub_socket, u'pyin', {u'code':code},parent=parent)
         md = self._make_metadata(parent['metadata'])
         try:
             working = shell.user_ns
 
             prefix = "_"+str(msg_id).replace("-","")+"_"
 
             f,args,kwargs = unpack_apply_message(bufs, working, copy=False)
 
             fname = getattr(f, '__name__', 'f')
 
             fname = prefix+"f"
             argname = prefix+"args"
             kwargname = prefix+"kwargs"
             resultname = prefix+"result"
 
             ns = { fname : f, argname : args, kwargname : kwargs , resultname : None }
             # print ns
             working.update(ns)
             code = "%s = %s(*%s,**%s)" % (resultname, fname, argname, kwargname)
             try:
                 exec code in shell.user_global_ns, shell.user_ns
                 result = working.get(resultname)
             finally:
                 for key in ns.iterkeys():
                     working.pop(key)
 
             result_buf = serialize_object(result,
                 buffer_threshold=self.session.buffer_threshold,
                 item_threshold=self.session.item_threshold,
             )
         
         except:
             # invoke IPython traceback formatting
             shell.showtraceback()
             # FIXME - fish exception info out of shell, possibly left there by
             # run_code.  We'll need to clean up this logic later.
             reply_content = {}
             if shell._reply_content is not None:
                 reply_content.update(shell._reply_content)
                 e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='apply')
                 reply_content['engine_info'] = e_info
                 # reset after use
                 shell._reply_content = None
             
             self.session.send(self.iopub_socket, u'pyerr', reply_content, parent=parent,
                                 ident=self._topic('pyerr'))
             self.log.info("Exception in apply request:\n%s", '\n'.join(reply_content['traceback']))
             result_buf = []
 
             if reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
         else:
             reply_content = {'status' : 'ok'}
 
         # put 'ok'/'error' status in header, for scheduler introspection:
         md['status'] = reply_content['status']
 
         # flush i/o
         sys.stdout.flush()
         sys.stderr.flush()
         
         reply_msg = self.session.send(stream, u'apply_reply', reply_content,
                     parent=parent, ident=ident,buffers=result_buf, metadata=md)
 
         self._publish_status(u'idle', parent)
 
     #---------------------------------------------------------------------------
     # Control messages
     #---------------------------------------------------------------------------
 
     def abort_request(self, stream, ident, parent):
         """abort a specifig msg by id"""
         msg_ids = parent['content'].get('msg_ids', None)
         if isinstance(msg_ids, basestring):
             msg_ids = [msg_ids]
         if not msg_ids:
             self.abort_queues()
         for mid in msg_ids:
             self.aborted.add(str(mid))
 
         content = dict(status='ok')
         reply_msg = self.session.send(stream, 'abort_reply', content=content,
                 parent=parent, ident=ident)
         self.log.debug("%s", reply_msg)
 
     def clear_request(self, stream, idents, parent):
         """Clear our namespace."""
         self.shell.reset(False)
         msg = self.session.send(stream, 'clear_reply', ident=idents, parent=parent,
                 content = dict(status='ok'))
 
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _wrap_exception(self, method=None):
         # import here, because _wrap_exception is only used in parallel,
         # and parallel has higher min pyzmq version
         from IPython.parallel.error import wrap_exception
         e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method=method)
         content = wrap_exception(e_info)
         return content
 
     def _topic(self, topic):
         """prefixed topic for IOPub messages"""
         if self.int_id >= 0:
             base = "engine.%i" % self.int_id
         else:
             base = "kernel.%s" % self.ident
         
         return py3compat.cast_bytes("%s.%s" % (base, topic))
     
     def _abort_queues(self):
         for stream in self.shell_streams:
             if stream:
                 self._abort_queue(stream)
 
     def _abort_queue(self, stream):
         poller = zmq.Poller()
         poller.register(stream.socket, zmq.POLLIN)
         while True:
             idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
             if msg is None:
                 return
 
             self.log.info("Aborting:")
             self.log.info("%s", msg)
             msg_type = msg['header']['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
 
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             self.log.debug("%s", reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             poller.poll(50)
 
 
     def _no_raw_input(self):
         """Raise StdinNotImplentedError if active frontend doesn't support
         stdin."""
         raise StdinNotImplementedError("raw_input was called, but this "
                                        "frontend does not support stdin.") 
         
     def _raw_input(self, prompt, ident, parent):
         # Flush output before making the request.
         sys.stderr.flush()
         sys.stdout.flush()
         # flush the stdin socket, to purge stale replies
         while True:
             try:
                 self.stdin_socket.recv_multipart(zmq.NOBLOCK)
             except zmq.ZMQError as e:
                 if e.errno == zmq.EAGAIN:
                     break
                 else:
                     raise
         
         # Send the input request.
         content = json_clean(dict(prompt=prompt))
         self.session.send(self.stdin_socket, u'input_request', content, parent,
                           ident=ident)
 
         # Await a response.
         while True:
             try:
                 ident, reply = self.session.recv(self.stdin_socket, 0)
             except Exception:
                 self.log.warn("Invalid Message:", exc_info=True)
             except KeyboardInterrupt:
                 # re-raise KeyboardInterrupt, to truncate traceback
                 raise KeyboardInterrupt
             else:
                 break
         try:
             value = py3compat.unicode_to_str(reply['content']['value'])
         except:
             self.log.error("Got bad raw_input reply: ")
             self.log.error("%s", parent)
             value = ''
         if value == '\x04':
             # EOF
             raise EOFError
         return value
 
     def _complete(self, msg):
         c = msg['content']
         try:
             cpos = int(c['cursor_pos'])
         except:
             # If we don't get something that we can convert to an integer, at
             # least attempt the completion guessing the cursor is at the end of
             # the text, if there's any, and otherwise of the line
             cpos = len(c['text'])
             if cpos==0:
                 cpos = len(c['line'])
         return self.shell.complete(c['text'], c['line'], cpos)
 
     def _at_shutdown(self):
         """Actions taken at shutdown by the kernel, called by python's atexit.
         """
         # io.rprint("Kernel at_shutdown") # dbg
         if self._shutdown_message is not None:
             self.session.send(self.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
             self.log.debug("%s", self._shutdown_message)
         [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]
 

examples/notebooks/Frontend-Kernel Model.ipynb

@@ -1,271 +1,322
 {
  "metadata": {
-  "name": "Frontend-Kernel Model"
+  "name": ""
  },
  "nbformat": 3,
  "nbformat_minor": 0,
  "worksheets": [
   {
    "cells": [
     {
      "cell_type": "heading",
      "level": 1,
      "metadata": {},
      "source": [
       "The Frontend/Kernel Model"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The traditional IPython (`ipython`) consists of a single process that combines a terminal based UI with the process that runs the users code.\n",
       "\n",
       "While this traditional application still exists, the modern IPython consists of two processes:\n",
       "\n",
       "* Kernel: this is the process that runs the users code.\n",
       "* Frontend: this is the process that provides the user interface where the user types code and sees results.\n",
       "\n",
       "IPython currently has 3 frontends:\n",
       "\n",
       "* Terminal Console (`ipython console`)\n",
       "* Qt Console (`ipython qtconsole`)\n",
       "* Notebook (`ipython notebook`)\n",
       "\n",
       "The Kernel and Frontend communicate over a ZeroMQ/JSON based messaging protocol, which allows multiple Frontends (even of different types) to communicate with a single Kernel. This opens the door for all sorts of interesting things, such as connecting a Console or Qt Console to a Notebook's Kernel.  For example, you may want to connect a Qt console to your Notebook's Kernel and use it as a help\n",
       "browser, calling `??` on objects in the Qt console (whose pager is more flexible than the\n",
       "one in the notebook).  \n",
       "\n",
       "This Notebook describes how you would connect another Frontend to a Kernel that is associated with a Notebook."
      ]
     },
     {
      "cell_type": "heading",
      "level": 2,
      "metadata": {},
      "source": [
       "Manual connection"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "To connect another Frontend to a Kernel manually, you first need to find out the connection information for the Kernel using the `%connect_info` magic:"
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "%connect_info"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "{\n",
         "  \"stdin_port\": 52858, \n",
         "  \"ip\": \"127.0.0.1\", \n",
         "  \"hb_port\": 52859, \n",
         "  \"key\": \"7efd45ca-d8a2-41b0-9cea-d9116d0fb883\", \n",
         "  \"shell_port\": 52856, \n",
         "  \"iopub_port\": 52857\n",
         "}\n",
         "\n",
         "Paste the above JSON into a file, and connect with:\n",
         "    $> ipython <app> --existing <file>\n",
         "or, if you are local, you can connect with just:\n",
         "    $> ipython <app> --existing kernel-b3bac7c1-8b2c-4536-8082-8d1df24f99ac.json \n",
         "or even just:\n",
         "    $> ipython <app> --existing \n",
         "if this is the most recent IPython session you have started.\n"
        ]
       }
      ],
      "prompt_number": 6
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "You can see that this magic displays everything you need to connect to this Notebook's Kernel."
      ]
     },
     {
      "cell_type": "heading",
      "level": 2,
      "metadata": {},
      "source": [
       "Automatic connection using a new Qt Console"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "You can also start a new Qt Console connected to your current Kernel by using the `%qtconsole` magic. This will detect the necessary connection\n",
       "information and start the Qt Console for you automatically."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "a = 10"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 1
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "%qtconsole"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [],
      "prompt_number": 2
     },
     {
      "cell_type": "heading",
      "level": 2,
      "metadata": {},
      "source": [
       "The kernel's `raw_input` and `%debug`"
      ]
     },
     {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
       "The Notebook has added support for `raw_input` and `%debug`, as of 1.0."
      ]
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
+      "# Python 3 compat\n",
+      "try:\n",
+      "    raw_input\n",
+      "except NameError:\n",
+      "    raw_input = input"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
       "name = raw_input(\"What is your name? \")\n",
       "name"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "name": "stdout",
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "What is your name? Sir Robin\n"
        ]
       },
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 1,
+       "prompt_number": 2,
        "text": [
-        "u'Sir Robin'"
+        "'Sir Robin'"
        ]
       }
      ],
-     "prompt_number": 1
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "**Python 2-only**: the eval input works as well (`input` is just `eval(raw_input(prompt))`)"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "fingers = input(\"How many fingers? \")\n",
+      "fingers, type(fingers)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "name": "stdout",
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "How many fingers? 4\n"
+       ]
+      },
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 3,
+       "text": [
+        "(4, int)"
+       ]
+      }
+     ],
+     "prompt_number": 3
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "def div(x, y):\n",
       "    return x/y\n",
       "\n",
       "div(1,0)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "ename": "ZeroDivisionError",
        "evalue": "integer division or modulo by zero",
        "output_type": "pyerr",
        "traceback": [
         "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[1;31mZeroDivisionError\u001b[0m                         Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-2-a5097cc0c0c5>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[0;32m      2\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[0my\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      3\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 4\u001b[1;33m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
-        "\u001b[1;32m<ipython-input-2-a5097cc0c0c5>\u001b[0m in \u001b[0;36mdiv\u001b[1;34m(x, y)\u001b[0m\n\u001b[0;32m      1\u001b[0m \u001b[1;32mdef\u001b[0m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mx\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0my\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 2\u001b[1;33m     \u001b[1;32mreturn\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[0my\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      3\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      4\u001b[0m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
+        "\u001b[1;32m<ipython-input-4-a5097cc0c0c5>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[0;32m      2\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[0my\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      3\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 4\u001b[1;33m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
+        "\u001b[1;32m<ipython-input-4-a5097cc0c0c5>\u001b[0m in \u001b[0;36mdiv\u001b[1;34m(x, y)\u001b[0m\n\u001b[0;32m      1\u001b[0m \u001b[1;32mdef\u001b[0m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mx\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0my\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 2\u001b[1;33m     \u001b[1;32mreturn\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[0my\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      3\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      4\u001b[0m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
         "\u001b[1;31mZeroDivisionError\u001b[0m: integer division or modulo by zero"
        ]
       }
      ],
-     "prompt_number": 2
+     "prompt_number": 4
     },
     {
      "cell_type": "code",
      "collapsed": false,
      "input": [
       "%debug"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
-        "> \u001b[1;32m<ipython-input-2-a5097cc0c0c5>\u001b[0m(2)\u001b[0;36mdiv\u001b[1;34m()\u001b[0m\n",
+        "> \u001b[1;32m<ipython-input-4-a5097cc0c0c5>\u001b[0m(2)\u001b[0;36mdiv\u001b[1;34m()\u001b[0m\n",
         "\u001b[1;32m      1 \u001b[1;33m\u001b[1;32mdef\u001b[0m \u001b[0mdiv\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mx\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0my\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
         "\u001b[0m\u001b[1;32m----> 2 \u001b[1;33m    \u001b[1;32mreturn\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[0my\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
         "\u001b[0m\u001b[1;32m      3 \u001b[1;33m\u001b[1;33m\u001b[0m\u001b[0m\n",
         "\u001b[0m\n"
        ]
       },
       {
        "name": "stdout",
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "ipdb> x\n"
        ]
       },
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "1\n"
        ]
       },
       {
        "name": "stdout",
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "ipdb> y\n"
        ]
       },
       {
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "0\n"
        ]
       },
       {
        "name": "stdout",
        "output_type": "stream",
        "stream": "stdout",
        "text": [
         "ipdb> exit\n"
        ]
       }
      ],
-     "prompt_number": 3
+     "prompt_number": 5
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file