    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3B1C2D4'.  Only compress the string if it saves space.\n",
      "\n",
      "* [Constraints](#Constraints)\n",
      "* [Test Cases](#Test-Cases)\n",
      "* [Algorithm](#Algorithm)\n",
      "* [Code](#Code)\n",
 
</s> remove     "* 'AAABCCDDDD' -> 'A3B1C2D4'"
 </s> add     "* 'AAABCCDDDD' -> 'A3BCCD4'" </s> remove    "display_name": "Python 2",
 </s> add    "display_name": "Python 3", </s> remove    "name": "python2"
 </s> add    "name": "python3" </s> remove     "version": 2
 </s> add     "version": 3 </s> remove     "        assert_equal(func('AAABCCDDDD'), 'A3B1C2D4')\n",
 </s> add     "        assert_equal(func('AAABCCDDDD'), 'A3BCCD4')\n",
    "## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3BCCD4'.  Only compress the string if it saves space.\n",
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
    "## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3BCCD4'.  Only compress the string if it saves space.\n",
      "\n",
      "* [Constraints](#Constraints)\n",
      "* [Test Cases](#Test-Cases)\n",
      "* [Algorithm](#Algorithm)\n",
      "* [Code](#Code)\n",
keep keep keep keep replace keep keep keep keep keep
 Added the same changes to test cases in the challenge notebook 
arrays_strings/compress/compress_challenge.ipynb