Bug in programmatic notebook creation?

ProgrammaticNotebook-v4.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Creating an IPython Notebook programatically"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "import IPython.nbformat as nbf"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Let's create the new notebook object first:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "nb = nbf.v4.new_notebook()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "For this example, we populate it with a simple text cell and one with code. Empty notebooks are OK too, this is just for illustration purposes:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "text = \"This is an auto-generated notebook.\"\n",
    "code = \"1+2\"\n",
    "\n",
    "nb['cells'] = [nbf.v4.new_markdown_cell(text),\n",
    "               nbf.v4.new_code_cell(code) ]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Next, we write it to a file on disk that we can then open as a new notebook.\n",
    "\n",
    "Note: This should be as easy as: `nbf.write(nb, fname)`, but the current api is a little more verbose and needs a real file-like\n",
    "object. We're fixing that."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "filename = 'test.ipynb'\n",
    "\n",
    "with open(filename, 'w') as f:\n",
    "    nbf.write(nb, f)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "This notebook can be run at the command line with:\n",
    "\n",
    "    ipython -c '%run test.ipynb'\n",
    "\n",
    "Or you can open it [as a live notebook](test.ipynb)."
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "IPython (Python 2)",
   "name": "python2"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 2
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython2",
   "version": "2.7.5+"
  },
  "signature": "sha256:daf65ba716d91340958662ecb313dece45cefb4286ed0aeb9e7f8c73ffd4b595"
 },
 "nbformat": 4,
 "nbformat_minor": 0
}