One more exercise

fibonacci.py

-def fib(n):
-    if n == 0:
-        return 0
-    if n == 1:
-        return 1
-    return fib(n - 1) + fib(n - 2)
-
-if __name__ == '__main__':
-    for n in range(5, 10):
-        print 'fib({0}) = {1}'.format(n, fib(n))

python.ipynb

@@ -784,7 +784,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "type('an example string')"
+      "type('I am a homo sapiens')"
      ],
      "language": "python",
      "metadata": {},
@@ -792,13 +792,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 21,
+       "prompt_number": 11,
        "text": [
         "str"
        ]
       }
      ],
-     "prompt_number": 21
+     "prompt_number": 11
     },
     {
      "cell_type": "markdown",
@@ -818,7 +818,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "'abc' * 5 + 'def'"
+      "'beer' * 5 + 'whiskey'"
      ],
      "language": "python",
      "metadata": {},
@@ -826,13 +826,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 22,
+       "prompt_number": 12,
        "text": [
-        "'abcabcabcabcabcdef'"
+        "'beerbeerbeerbeerbeerwhiskey'"
        ]
       }
      ],
-     "prompt_number": 22
+     "prompt_number": 12
     },
     {
      "cell_type": "markdown",
@@ -845,7 +845,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "a = 'abc'\n",
+      "a = 'spezi'\n",
       "type(a)"
      ],
      "language": "python",
@@ -854,13 +854,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 23,
+       "prompt_number": 13,
        "text": [
         "str"
        ]
       }
      ],
-     "prompt_number": 23
+     "prompt_number": 13
     },
     {
      "cell_type": "markdown",
@@ -873,7 +873,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "'abc' + 34"
+      "'beer' + 34"
      ],
      "language": "python",
      "metadata": {},
@@ -884,12 +884,12 @@
        "output_type": "pyerr",
        "traceback": [
         "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[1;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-24-43a6c1044bb0>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[1;34m'abc'\u001b[0m \u001b[1;33m+\u001b[0m \u001b[1;36m34\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
+        "\u001b[1;32m<ipython-input-14-ec918fbfdf41>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[1;34m'beer'\u001b[0m \u001b[1;33m+\u001b[0m \u001b[1;36m34\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
         "\u001b[1;31mTypeError\u001b[0m: cannot concatenate 'str' and 'int' objects"
        ]
       }
      ],
-     "prompt_number": 24
+     "prompt_number": 14
     },
     {
      "cell_type": "markdown",
@@ -1368,7 +1368,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "len('abcdefghijkl')"
+      "len('attacgataggcatccgt')"
      ],
      "language": "python",
      "metadata": {},
@@ -1376,13 +1376,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 39,
+       "prompt_number": 15,
        "text": [
-        "12"
+        "18"
        ]
       }
      ],
-     "prompt_number": 39
+     "prompt_number": 15
     },
     {
      "cell_type": "code",
@@ -1408,7 +1408,7 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "('abc', 22, True, 'abc').count('abc')"
+      "('atg', 22, True, 'atg').count('atg')"
      ],
      "language": "python",
      "metadata": {},
@@ -1416,13 +1416,13 @@
       {
        "metadata": {},
        "output_type": "pyout",
-       "prompt_number": 41,
+       "prompt_number": 16,
        "text": [
         "2"
        ]
       }
      ],
-     "prompt_number": 41
+     "prompt_number": 16
     },
     {
      "cell_type": "markdown",
@@ -3530,6 +3530,22 @@
       "    b = a"
      ]
     },
+    {
+     "cell_type": "markdown",
+     "metadata": {
+      "slideshow": {
+       "slide_type": "slide"
+      }
+     },
+     "source": [
+      "$\\S$ Exercise: Running code from a file\n",
+      "===\n",
+      "\n",
+      "* Save your k-mer counting code to a file `kmer_counting.py`.\n",
+      "* Include some code using it on an example string and printing the results.\n",
+      "* Run the code from the command line."
+     ]
+    },
     {
      "cell_type": "markdown",
      "metadata": {