Nicer prompt formatting in zmqterminal, and use print_function.

IPython/frontend/zmqterminal/frontend.py

@@ -1,260 +1,259 b''
 # -*- coding: utf-8 -*-
 """Frontend of ipython working with python-zmq
 
 Ipython's frontend, is a ipython interface that send request to kernel and proccess the kernel's outputs.
 
 For more details, see the ipython-zmq design
 """
 #-----------------------------------------------------------------------------
 # Copyright (C) 2010 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
 #-----------------------------------------------------------------------------
+from __future__ import print_function
 
 import __builtin__
 import sys
 import os
 from Queue import Empty
 import readline
 import rlcompleter
 
 #-----------------------------------------------------------------------------
 # Imports from ipython
 #-----------------------------------------------------------------------------
 from IPython.external.argparse import ArgumentParser
 from IPython.core.inputsplitter import IPythonInputSplitter
 from IPython.zmq.blockingkernelmanager import BlockingKernelManager as KernelManager
 from IPython.frontend.zmqterminal.completer import ClientCompleter2p 
 
 #-----------------------------------------------------------------------------
 # Network Constants
 #-----------------------------------------------------------------------------
 
 from IPython.utils.localinterfaces import LOCALHOST, LOCAL_IPS
 class Frontend(object):
     """This class is a simple frontend to ipython-zmq 
        
       NOTE: this class uses kernelmanager to manipulate sockets
       
       Parameters:
       -----------
       kernelmanager : object
         instantiated object from class KernelManager in module kernelmanager
         
     """
 
     def __init__(self, kernelmanager):
        self.km = kernelmanager
        self.session_id = self.km.session.session
        self.completer = ClientCompleter2p(self, self.km)
        readline.parse_and_bind("tab: complete")
        readline.parse_and_bind('set show-all-if-ambiguous on')
        readline.set_completer(self.completer.complete)
 
        history_path = os.path.expanduser('~/.ipython/history')
        if os.path.isfile(history_path):
            rlcompleter.readline.read_history_file(history_path)
        else:
            print("history file cannot be read.")   
 
        self.messages = {}
 
        self._splitter = IPythonInputSplitter()
        self.code = ""
  
        self.prompt_count = 0
        self._get_initial_prompt()
  
     def _get_initial_prompt(self):
        self._execute('', hidden=True)
    
     def interact(self):
        """Gets input from console using inputsplitter, then
        while you enter code it can indent and set index id to any input
        """    
        
        try:
-           self._splitter.push(raw_input('In[%i]:'%self.prompt_count+self.code))
+           print()
+           self._splitter.push(raw_input(' In[%i]: '%self.prompt_count+self.code))
            while self._splitter.push_accepts_more():
-              self.code = raw_input('.....:'+' '*self._splitter.indent_spaces)
+              self.code = raw_input(' .....: '+' '*self._splitter.indent_spaces)
               self._splitter.push(' '*self._splitter.indent_spaces+self.code)
            self._execute(self._splitter.source,False)
            self._splitter.reset()
        except KeyboardInterrupt:
            print('\nKeyboardInterrupt\n')
            pass
           
        
     def start(self):
        """Start the interaction loop, calling the .interact() method for each
        input cell.
        """
        while True:
            try:
                self.interact()
            except KeyboardInterrupt:
                 print('\nKeyboardInterrupt\n')
                 pass
            except EOFError:
                answer = ''    
                while True:
                    answer = raw_input('\nDo you really want to exit ([y]/n)?')
                    if answer == 'y' or answer == '' :
                        self.km.shutdown_kernel()
                        sys.exit()
                    elif answer == 'n':
                        break
 
     def _execute(self, source, hidden = True):
         """ Execute 'source'. If 'hidden', do not show any output.
 
         See parent class :meth:`execute` docstring for full details.
         """
         msg_id = self.km.xreq_channel.execute(source, hidden)
         while not self.km.xreq_channel.msg_ready():
             try:
                 self.handle_rep_channel(timeout=0.1)
             except Empty:
                 pass
         self.handle_execute_reply(msg_id)
 
     def handle_execute_reply(self, msg_id):
         msg_xreq = self.km.xreq_channel.get_msg()
         if msg_xreq["parent_header"]["msg_id"] == msg_id:
             if msg_xreq["content"]["status"] == 'ok' :
                 self.handle_sub_channel()
-                self.prompt_count = msg_xreq["content"]["execution_count"] + 1
                
-            else:
-                etb = msg_xreq["content"]["traceback"]
-                print >> sys.stderr, etb[0]
-                try:        # These bits aren't there for a SyntaxError
-                    print >> sys.stderr, etb[1]
-                    print >> sys.stderr, etb[2]
-                except IndexError:
-                    pass
-                self.prompt_count = msg_xreq["content"]["execution_count"] + 1
+            elif msg_xreq["content"]["status"] == 'error':
+                for frame in msg_xreq["content"]["traceback"]:
+                    print(frame, file=sys.stderr)
+            
+            self.prompt_count = msg_xreq["content"]["execution_count"] + 1
 
 
     def handle_sub_channel(self):
        """ Method to procces subscribe channel's messages
 
            This method reads a message and processes the content in different
            outputs like stdout, stderr, pyout and status
 
            Arguments:
            sub_msg:  message receive from kernel in the sub socket channel
                      capture by kernel manager.
        """
        while self.km.sub_channel.msg_ready():
            sub_msg = self.km.sub_channel.get_msg()
            if self.session_id == sub_msg['parent_header']['session']:
                if sub_msg['msg_type'] == 'status' :
                     if sub_msg["content"]["execution_state"] == "busy" :
                         pass
 
                elif sub_msg['msg_type'] == 'stream' :
                   if sub_msg["content"]["name"] == "stdout":
-                    print >> sys.stdout, sub_msg["content"]["data"]
+                    print(sub_msg["content"]["data"], file=sys.stdout, end="")
                     sys.stdout.flush()
                   elif sub_msg["content"]["name"] == "stderr" :
-                    print >> sys.stderr, sub_msg["content"]["data"]
+                    print(sub_msg["content"]["data"], file=sys.stderr, end="")
                     sys.stderr.flush()
                 
                elif sub_msg['msg_type'] == 'pyout' :
-                    print >> sys.stdout,"Out[%i]:"%sub_msg["content"]["execution_count"], sub_msg["content"]["data"]["text/plain"]
+                    print("Out[%i]:"%sub_msg["content"]["execution_count"],
+                            sub_msg["content"]["data"]["text/plain"],
+                            file=sys.stdout)
                     sys.stdout.flush()
 
     def handle_rep_channel(self, timeout=0.1):
         """ Method to capture raw_input
         """
         msg_rep = self.km.rep_channel.get_msg(timeout=timeout)
         if self.session_id == msg_rep["parent_header"]["session"] :
             raw_data = raw_input(msg_rep["content"]["prompt"])
             self.km.rep_channel.input(raw_data)
              
        
 
        
 def start_frontend():
     """ Entry point for application.
     
     """
     # Parse command line arguments.
     parser = ArgumentParser()
     kgroup = parser.add_argument_group('kernel options')
     kgroup.add_argument('-e', '--existing', action='store_true',
                         help='connect to an existing kernel')
     kgroup.add_argument('--ip', type=str, default=LOCALHOST,
                         help=\
             "set the kernel\'s IP address [default localhost].\
             If the IP address is something other than localhost, then \
             Consoles on other machines will be able to connect\
             to the Kernel, so be careful!")
     kgroup.add_argument('--xreq', type=int, metavar='PORT', default=0,
                         help='set the XREQ channel port [default random]')
     kgroup.add_argument('--sub', type=int, metavar='PORT', default=0,
                         help='set the SUB channel port [default random]')
     kgroup.add_argument('--rep', type=int, metavar='PORT', default=0,
                         help='set the REP channel port [default random]')
     kgroup.add_argument('--hb', type=int, metavar='PORT', default=0,
                         help='set the heartbeat port [default random]')
 
     egroup = kgroup.add_mutually_exclusive_group()
     egroup.add_argument('--pure', action='store_true', help = \
                         'use a pure Python kernel instead of an IPython kernel')
     egroup.add_argument('--pylab', type=str, metavar='GUI', nargs='?', 
                        const='auto', help = \
         "Pre-load matplotlib and numpy for interactive use. If GUI is not \
          given, the GUI backend is matplotlib's, otherwise use one of: \
          ['tk', 'gtk', 'qt', 'wx', 'inline'].")
     egroup.add_argument('--colors', type=str,
                         help="Set the color scheme (LightBG,Linux,NoColor). This is guessed\
                         based on the pygments style if not set.")
 
     args = parser.parse_args()
 
     # parse the colors arg down to current known labels
     if args.colors:
         colors=args.colors.lower()
         if colors in ('lightbg', 'light'):
             colors='lightbg'
         elif colors in ('dark', 'linux'):
             colors='linux'
         else:
             colors='nocolor'
     else:
         colors=None
 
     # Create a KernelManager and start a kernel.
     kernel_manager = KernelManager(xreq_address=(args.ip, args.xreq),
                                      sub_address=(args.ip, args.sub),
                                      rep_address=(args.ip, args.rep),
                                      hb_address=(args.ip, args.hb))
     if not args.existing:
         # if not args.ip in LOCAL_IPS+ALL_ALIAS:
         #     raise ValueError("Must bind a local ip, such as: %s"%LOCAL_IPS)
 
         kwargs = dict(ip=args.ip)
         if args.pure:
             kwargs['ipython']=False
         else:
             kwargs['colors']=colors
             if args.pylab:
                 kwargs['pylab']=args.pylab
         kernel_manager.start_kernel(**kwargs)
 
     
     kernel_manager.start_channels()
  
     frontend=Frontend(kernel_manager)
     return frontend
 
 if __name__ == "__main__" :
      frontend=start_frontend()
      frontend.start()