Start reproducing target notebook.

module2/exo1/toy_document_orgmode_python_en.org

-#+TITLE:  Your title
-#+AUTHOR: Your name
-#+DATE:   Today's date
+#+TITLE:  On the computation of pi
 #+LANGUAGE: en
-# #+PROPERTY: header-args :eval never-export
 
 #+HTML_HEAD: <link rel="stylesheet" type="text/css" href="http://www.pirilampo.org/styles/readtheorg/css/htmlize.css"/>
 #+HTML_HEAD: <link rel="stylesheet" type="text/css" href="http://www.pirilampo.org/styles/readtheorg/css/readtheorg.css"/>
@@ -11,6 +8,29 @@
 #+HTML_HEAD: <script type="text/javascript" src="http://www.pirilampo.org/styles/lib/js/jquery.stickytableheaders.js"></script>
 #+HTML_HEAD: <script type="text/javascript" src="http://www.pirilampo.org/styles/readtheorg/js/readtheorg.js"></script>
 
+# #+PROPERTY: header-args :eval never-export
+
+* Table of Contents
+
+* Asking the math library
+My computer tells me that \pi is /approximatively/
+
+#+begin_src python :results value :session :exports both
+from math import *
+pi
+#+end_src
+
+#+RESULTS:
+: 3.141592653589793
+
+* * Buffon's needle
+Applying the method of
+[[https://en.wikipedia.org/wiki/Buffon%2527s_needle_problem][Buffon's needle]] we get the *approximation*
+
+#+begin_src python :results value :session :exports both
+import numpy as np
+#+end_src
+
 * Some explanations
 
 This is an org-mode document with code examples in R.  Once opened in