:allow to donload enzyme*_namedtuple.py scripts

source/Collection_Data_Types.rst

@@ -537,7 +537,7 @@ the latter algorithm display the number of occurrence of each enzyme, But we can
 We will see how to do this later.
 
 Bonus
-"""""
+^^^^^
 
 There is another kind of tuple which allow to access to itmes by index or name.
 This data collection is called NamedTuple. The NamedTuple are not accessible directly they are in `collections` package,
@@ -565,6 +565,7 @@ The code must be adapted as below
    :linenos:
    :language: python
 
+:download:`enzymes_1_namedtuple.py <_static/code/enzyme_1_namedtuple.py>` .
 
 Exercise
 --------

source/Control_Flow_Statements.rst

@@ -212,11 +212,11 @@ and the 2 dna fragments: ::
 :download:`restriction.py <_static/code/restriction.py>` .
 
 Bonus
-"""""
+^^^^^
 
 If you prefer the enzyme implemeted as namedtuple
 
-:download:`restriction.py <_static/code/restriction_namedtuple.py>` .
+:download:`restriction_namedtuple.py <_static/code/restriction_namedtuple.py>` .
 
 
 Exercise