examples/Parallel Computing/Using Dill.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Using dill to pickle anything"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "IPython.parallel doesn't do much in the way of serialization.\n",
    "It has custom zero-copy handling of numpy arrays,\n",
    "but other than that, it doesn't do anything other than the bare minimum to make basic interactively defined functions and classes sendable.\n",
    "\n",
    "There are a few projects that extend pickle to make just about anything sendable, and one of these is [dill](http://www.cacr.caltech.edu/~mmckerns/dill).\n",
    "\n",
    "To install dill:\n",
    "        \n",
    "    pip install --pre dill"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "First, as always, we create a task function, this time with a closure"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "def make_closure(a):\n",
    "    \"\"\"make a function with a closure, and return it\"\"\"\n",
    "    def has_closure(b):\n",
    "        return a * b\n",
    "    return has_closure"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "closed = make_closure(5)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "10"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "closed(2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "import pickle"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Without help, pickle can't deal with closures"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "ename": "PicklingError",
     "evalue": "Can't pickle <function has_closure at 0x10412c6e0>: it's not found as __main__.has_closure",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[1;31mPicklingError\u001b[0m                             Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-5-0f1f376cfea0>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mpickle\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mdumps\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mclosed\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[1;32m/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc\u001b[0m in \u001b[0;36mdumps\u001b[1;34m(obj, protocol)\u001b[0m\n\u001b[0;32m   1372\u001b[0m \u001b[1;32mdef\u001b[0m \u001b[0mdumps\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mobj\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mprotocol\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mNone\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   1373\u001b[0m     \u001b[0mfile\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mStringIO\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m-> 1374\u001b[1;33m     \u001b[0mPickler\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfile\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mprotocol\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mdump\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mobj\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m   1375\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mfile\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mgetvalue\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   1376\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc\u001b[0m in \u001b[0;36mdump\u001b[1;34m(self, obj)\u001b[0m\n\u001b[0;32m    222\u001b[0m         \u001b[1;32mif\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mproto\u001b[0m \u001b[1;33m>=\u001b[0m \u001b[1;36m2\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    223\u001b[0m             \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mwrite\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mPROTO\u001b[0m \u001b[1;33m+\u001b[0m \u001b[0mchr\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mproto\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 224\u001b[1;33m         \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0msave\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mobj\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    225\u001b[0m         \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mwrite\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mSTOP\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    226\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc\u001b[0m in \u001b[0;36msave\u001b[1;34m(self, obj)\u001b[0m\n\u001b[0;32m    284\u001b[0m         \u001b[0mf\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mdispatch\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mget\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mt\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    285\u001b[0m         \u001b[1;32mif\u001b[0m \u001b[0mf\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 286\u001b[1;33m             \u001b[0mf\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mobj\u001b[0m\u001b[1;33m)\u001b[0m \u001b[1;31m# Call unbound method with explicit self\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    287\u001b[0m             \u001b[1;32mreturn\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    288\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc\u001b[0m in \u001b[0;36msave_global\u001b[1;34m(self, obj, name, pack)\u001b[0m\n\u001b[0;32m    746\u001b[0m             raise PicklingError(\n\u001b[0;32m    747\u001b[0m                 \u001b[1;34m\"Can't pickle %r: it's not found as %s.%s\"\u001b[0m \u001b[1;33m%\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 748\u001b[1;33m                 (obj, module, name))\n\u001b[0m\u001b[0;32m    749\u001b[0m         \u001b[1;32melse\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    750\u001b[0m             \u001b[1;32mif\u001b[0m \u001b[0mklass\u001b[0m \u001b[1;32mis\u001b[0m \u001b[1;32mnot\u001b[0m \u001b[0mobj\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mPicklingError\u001b[0m: Can't pickle <function has_closure at 0x10412c6e0>: it's not found as __main__.has_closure"
     ]
    }
   ],
   "source": [
    "pickle.dumps(closed)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "But after we import dill, magic happens"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "import dill"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "\"cdill.dill\\n_load_type\\np0\\n(S'FunctionType'\\np1\\ntp2\\nRp3\\n(cdill.dill...\""
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pickle.dumps(closed)[:64] + '...'"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "So from now on, pretty much everything is pickleable."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Now use this in IPython.parallel"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "As usual, we start by creating our Client and View"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "from IPython import parallel\n",
    "rc = parallel.Client()\n",
    "view = rc.load_balanced_view()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Now let's try sending our function with a closure:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "ename": "ValueError",
     "evalue": "Sorry, cannot pickle code objects with closures",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[1;31mValueError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-9-23a646829fdc>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mview\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mapply_sync\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mclosed\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;36m3\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36mapply_sync\u001b[1;34m(self, f, *args, **kwargs)\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36mspin_after\u001b[1;34m(f, self, *args, **kwargs)\u001b[0m\n\u001b[0;32m     73\u001b[0m \u001b[1;32mdef\u001b[0m \u001b[0mspin_after\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mf\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     74\u001b[0m     \u001b[1;34m\"\"\"call spin after the method.\"\"\"\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 75\u001b[1;33m     \u001b[0mret\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mf\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     76\u001b[0m     \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mspin\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     77\u001b[0m     \u001b[1;32mreturn\u001b[0m \u001b[0mret\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36mapply_sync\u001b[1;34m(self, f, *args, **kwargs)\u001b[0m\n\u001b[0;32m    245\u001b[0m          \u001b[0mreturning\u001b[0m \u001b[0mthe\u001b[0m \u001b[0mresult\u001b[0m\u001b[1;33m.\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    246\u001b[0m         \"\"\"\n\u001b[1;32m--> 247\u001b[1;33m         \u001b[1;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0m_really_apply\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mf\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0margs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mkwargs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mblock\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mTrue\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    248\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    249\u001b[0m     \u001b[1;31m#----------------------------------------------------------------\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36m_really_apply\u001b[1;34m(self, f, args, kwargs, block, track, after, follow, timeout, targets, retries)\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36msync_results\u001b[1;34m(f, self, *args, **kwargs)\u001b[0m\n\u001b[0;32m     64\u001b[0m     \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0m_in_sync_results\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mTrue\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     65\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 66\u001b[1;33m         \u001b[0mret\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mf\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     67\u001b[0m     \u001b[1;32mfinally\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     68\u001b[0m         \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0m_in_sync_results\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mFalse\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36m_really_apply\u001b[1;34m(self, f, args, kwargs, block, track, after, follow, timeout, targets, retries)\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36msave_ids\u001b[1;34m(f, self, *args, **kwargs)\u001b[0m\n\u001b[0;32m     49\u001b[0m     \u001b[0mn_previous\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mlen\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mclient\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mhistory\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     50\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 51\u001b[1;33m         \u001b[0mret\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mf\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     52\u001b[0m     \u001b[1;32mfinally\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     53\u001b[0m         \u001b[0mnmsgs\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mlen\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mclient\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mhistory\u001b[0m\u001b[1;33m)\u001b[0m \u001b[1;33m-\u001b[0m \u001b[0mn_previous\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/view.pyc\u001b[0m in \u001b[0;36m_really_apply\u001b[1;34m(self, f, args, kwargs, block, track, after, follow, timeout, targets, retries)\u001b[0m\n\u001b[0;32m   1049\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   1050\u001b[0m         msg = self.client.send_apply_request(self._socket, f, args, kwargs, track=track,\n\u001b[1;32m-> 1051\u001b[1;33m                                 metadata=metadata)\n\u001b[0m\u001b[0;32m   1052\u001b[0m         \u001b[0mtracker\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mNone\u001b[0m \u001b[1;32mif\u001b[0m \u001b[0mtrack\u001b[0m \u001b[1;32mis\u001b[0m \u001b[0mFalse\u001b[0m \u001b[1;32melse\u001b[0m \u001b[0mmsg\u001b[0m\u001b[1;33m[\u001b[0m\u001b[1;34m'tracker'\u001b[0m\u001b[1;33m]\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   1053\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/parallel/client/client.pyc\u001b[0m in \u001b[0;36msend_apply_request\u001b[1;34m(self, socket, f, args, kwargs, metadata, track, ident)\u001b[0m\n\u001b[0;32m   1252\u001b[0m         bufs = serialize.pack_apply_message(f, args, kwargs,\n\u001b[0;32m   1253\u001b[0m             \u001b[0mbuffer_threshold\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0msession\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mbuffer_threshold\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m-> 1254\u001b[1;33m             \u001b[0mitem_threshold\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0msession\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mitem_threshold\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m   1255\u001b[0m         )\n\u001b[0;32m   1256\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/kernel/zmq/serialize.pyc\u001b[0m in \u001b[0;36mpack_apply_message\u001b[1;34m(f, args, kwargs, buffer_threshold, item_threshold)\u001b[0m\n\u001b[0;32m    163\u001b[0m     \u001b[0minfo\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mdict\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mnargs\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mlen\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mnarg_bufs\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mlen\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0marg_bufs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mkw_keys\u001b[0m\u001b[1;33m=\u001b[0m\u001b[0mkw_keys\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    164\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 165\u001b[1;33m     \u001b[0mmsg\u001b[0m \u001b[1;33m=\u001b[0m \u001b[1;33m[\u001b[0m\u001b[0mpickle\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mdumps\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mcan\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mf\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;33m-\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m]\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    166\u001b[0m     \u001b[0mmsg\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mappend\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mpickle\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mdumps\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0minfo\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m-\u001b[0m\u001b[1;36m1\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    167\u001b[0m     \u001b[0mmsg\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mextend\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0marg_bufs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;32m/Users/minrk/dev/ip/mine/IPython/utils/codeutil.pyc\u001b[0m in \u001b[0;36mreduce_code\u001b[1;34m(co)\u001b[0m\n\u001b[0;32m     36\u001b[0m \u001b[1;32mdef\u001b[0m \u001b[0mreduce_code\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mco\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m     37\u001b[0m     \u001b[1;32mif\u001b[0m \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_freevars\u001b[0m \u001b[1;32mor\u001b[0m \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_cellvars\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m---> 38\u001b[1;33m         \u001b[1;32mraise\u001b[0m \u001b[0mValueError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"Sorry, cannot pickle code objects with closures\"\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m     39\u001b[0m     args =  [co.co_argcount, co.co_nlocals, co.co_stacksize,\n\u001b[0;32m     40\u001b[0m             \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_flags\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_code\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_consts\u001b[0m\u001b[1;33m,\u001b[0m \u001b[0mco\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mco_names\u001b[0m\u001b[1;33m,\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mValueError\u001b[0m: Sorry, cannot pickle code objects with closures"
     ]
    }
   ],
   "source": [
    "view.apply_sync(closed, 3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Oops, no dice. For IPython to work with dill,\n",
    "there are one or two more steps. IPython will do these for you if you call `DirectView.use_dill`:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<AsyncResult: use_dill>"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rc[:].use_dill()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This is equivalent to\n",
    "\n",
    "```python\n",
    "from IPython.utils.pickleutil import use_dill\n",
    "use_dill()\n",
    "rc[:].apply(use_dill)\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Now let's try again"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "15"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "view.apply_sync(closed, 3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Yay! Now we can use dill to allow IPython.parallel to send anything.\n",
    "\n",
    "And that's it! We can send closures and other previously non-pickleables to our engines.\n",
    "\n",
    "Let's give it a try now:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "20"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "remote_closure = view.apply_sync(make_closure, 4)\n",
    "remote_closure(5)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "But wait, there's more!\n",
    "\n",
    "At this point, we can send/recv all kinds of stuff"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "def outer(a):\n",
    "    def inner(b):\n",
    "        def inner_again(c):\n",
    "            return c * b * a\n",
    "        return inner_again\n",
    "    return inner"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "So outer returns a function with a closure, which returns a function with a closure.\n",
    "\n",
    "Now, we can resolve the first closure on the engine, the second here, and the third on a different engine,\n",
    "after passing through a lambda we define here and call there, just for good measure."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "6"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "view.apply_sync(lambda f: f(3),view.apply_sync(outer, 1)(2))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "And for good measure, let's test that normal execution still works:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[5, 5, 5, 5, 5, 5, 5, 5]\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "[10, 10, 10, 10, 10, 10, 10, 10]"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "%px foo = 5\n",
    "\n",
    "print(rc[:]['foo'])\n",
    "rc[:]['bar'] = lambda : 2 * foo\n",
    "rc[:].apply_sync(parallel.Reference('bar'))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "And test that the `@interactive` decorator works"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Overwriting testdill.py\n"
     ]
    }
   ],
   "source": [
    "%%file testdill.py\n",
    "from IPython.parallel import interactive\n",
    "\n",
    "@interactive\n",
    "class C(object):\n",
    "    a = 5\n",
    "\n",
    "@interactive\n",
    "class D(C):\n",
    "    b = 10\n",
    "\n",
    "@interactive\n",
    "def foo(a):\n",
    "    return a * b\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "import testdill"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5 10\n"
     ]
    }
   ],
   "source": [
    "v = rc[-1]\n",
    "v['D'] = testdill.D\n",
    "d = v.apply_sync(lambda : D())\n",
    "print d.a, d.b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "50"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "v['b'] = 10\n",
    "v.apply_sync(testdill.foo, 5)"
   ]
  }
 ],
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  "gist_id": "5241793"
 },
 "nbformat": 4,
 "nbformat_minor": 0
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