diff --git a/python.ipynb b/python.ipynb
index dd9b92983beb15f2f35859a3331f0225ed9856e9..62f2eb376089e14291cff3ba8eee4570454fb32c 100644
--- a/python.ipynb
+++ b/python.ipynb
@@ -2631,36 +2631,6 @@
       "**Hint:** All elements in a set are unique."
      ]
     },
-    {
-     "cell_type": "markdown",
-     "metadata": {
-      "slideshow": {
-       "slide_type": "subslide"
-      }
-     },
-     "source": [
-      "$\\S$ Exercise: Analyse a repeat structure\n",
-      "===\n",
-      "\n",
-      "* Make a short tandem repeat that consists of three \"ACGT\" units and five \"TTATT\" units.\n",
-      "* Print all suffixes of the repeat structure."
-     ]
-    },
-    {
-     "cell_type": "markdown",
-     "metadata": {
-      "slideshow": {
-       "slide_type": "subslide"
-      }
-     },
-     "source": [
-      "$\\S$ Exercise: Analyse a repeat structure\n",
-      "===\n",
-      "\n",
-      "* Print all substrings of length 3.\n",
-      "* Print all unique substrings of length 3."
-     ]
-    },
     {
      "cell_type": "markdown",
      "metadata": {
@@ -2679,78 +2649,6 @@
       "    2 * (4 > 3)"
      ]
     },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "2 * 3 > 4"
-     ],
-     "language": "python",
-     "metadata": {
-      "slideshow": {
-       "slide_type": "fragment"
-      }
-     },
-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 9,
-       "text": [
-        "True"
-       ]
-      }
-     ],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "2 * (3 > 4)"
-     ],
-     "language": "python",
-     "metadata": {
-      "slideshow": {
-       "slide_type": "fragment"
-      }
-     },
-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 10,
-       "text": [
-        "0"
-       ]
-      }
-     ],
-     "prompt_number": 10
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "2 * (4 > 3)"
-     ],
-     "language": "python",
-     "metadata": {
-      "slideshow": {
-       "slide_type": "fragment"
-      }
-     },
-     "outputs": [
-      {
-       "metadata": {},
-       "output_type": "pyout",
-       "prompt_number": 11,
-       "text": [
-        "2"
-       ]
-      }
-     ],
-     "prompt_number": 11
-    },
     {
      "cell_type": "markdown",
      "metadata": {