Demo of hideable hints and scrubbing solutions from IPython notebooks

scrub_code.py

#!/usr/bin/env python
"""
simple example script for scrubping solution code cells from IPython notebooks

Usage: `scrub_code.py foo.ipynb [bar.ipynb [...]]`

Marked code cells are scrubbed from the notebook
"""

import io
import os
import sys

from IPython.nbformat.current import read, write

def scrub_code_cells(nb):
    scrubbed = 0
    cells = 0
    for ws in nb.worksheets:
        for cell in ws.cells:
            if cell.cell_type != 'code':
                continue
            cells += 1
            # scrub cells marked with initial '# Solution' comment
            # any other marker will do, or it could be unconditional
            if cell.input.startswith("# Solution"):
                cell.input = u'# Solution goes here'
                scrubbed += 1
                cell.outputs = []

    print
    print "scrubbed %i/%i code cells from notebook %s" % (scrubbed, cells, nb.metadata.name)

if __name__ == '__main__':
    for ipynb in sys.argv[1:]:
        print "scrubbing %s" % ipynb
        with io.open(ipynb, encoding='utf8') as f:
            nb = read(f, 'json')
        scrub_code_cells(nb)
        base, ext = os.path.splitext(ipynb)
        new_ipynb = "%s_scrub%s" % (base, ext)
        with io.open(new_ipynb, 'w', encoding='utf8') as f:
            write(nb, f, 'json')
        print "wrote %s" % new_ipynb

SWCDemo.ipynb

SWCDemo_scrub.py

{
 "metadata": {
  "name": "SWCDemo"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Initial cell has buttons to show/hide all hint cells"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "<script>\n",
      "    toggle_md_cell = function(divid) {\n",
      "        $(\"#\" + divid).parent().parent().toggle();\n",
      "    };\n",
      "    hide_all_hints = function() {\n",
      "        $(\"div.hint\").parent().parent().hide();\n",
      "    };\n",
      "    show_all_hints = function() {\n",
      "        $(\"div.hint\").parent().parent().show();\n",
      "    };\n",
      "</script>\n",
      "\n",
      "<button onclick=\"show_all_hints();\">show hints</button> <button onclick=\"hide_all_hints();\">hide hints</button>"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# this code cell isn't marked, so it survives\n",
      "print \"Welcome to Software Carpentry!\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Welcome to Software Carpentry!\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Problem 1"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Click this button to reveal a hint: <button onclick=\"toggle_md_cell('hint1');\">hint</button>"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## This is Hint # 1\n",
      "\n",
      "We mark each hint cell with an empty div:\n",
      "\n",
      "    <div id=\"hint2\" class=\"hint\"></div>\n",
      "\n",
      "<div id=\"hint1\" class=\"hint\"></div>"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Solution goes here"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Problem 2"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Click this button to reveal the next hint: <button onclick=\"toggle_md_cell('hint2');\">hint</button>"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "### This is Hint #2\n",
      "\n",
      "Here is how we are toggling hints:\n",
      "\n",
      "    <button onclick=\"toggle_md_cell('hint2');\">toggle hint</button>\n",
      "\n",
      "<div id=\"hint2\" class=\"hint\"></div>"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Solution goes here"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "*footer that hides all hints on load*\n",
      "\n",
      "Alternatively, one could add individual hides inside each hint cell,\n",
      "but this is the simplest way to hide all of them on page load.\n",
      "\n",
      "<script>\n",
      "    hide_all_hints();\n",
      "</script>"
     ]
    }
   ],
   "metadata": {}
  }
 ]
}