Merge pull request #3508 from minrk/raw_input

notebook supports raw_input and %debug now

examples/notebooks/Frontend-Kernel Model.ipynb

@@ -1,157 +1,271
 {
  "metadata": {
   "name": "Frontend-Kernel Model"
  },
  "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 one feature the notebook currently doesn't support as a Frontend is the ability to send data to the Kernel's standard input socket.  That is, if the Kernel requires information to be typed interactively by calling the builtin `raw_input` function, the Notebook will be blocked.  This happens for example if you run a script that queries interactively for parameters, and very importantly, is how the interactive IPython debugger that activates when you type `%debug` works.\n",
-      "\n",
-      "So, in order to be able to use `%debug` or anything else that requires `raw_input`, you can either use a Terminal Console or Qt Console connected to a Notebook's Kernel as described above.\n"
+      "The Notebook has added support for `raw_input` and `%debug`, as of 1.0."
      ]
+    },
+    {
+     "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,
+       "text": [
+        "u'Sir Robin'"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "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;31mZeroDivisionError\u001b[0m: integer division or modulo by zero"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "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      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
     }
    ],
    "metadata": {}
   }
  ]
 }
  No newline at end of file