diff --git a/source/Control_Flow_Statements.rst b/source/Control_Flow_Statements.rst
index 1e29fda04909e170f6534977ef56f2b76e77b387..258289b6361331ed755963286449a44e366dee19 100644
--- a/source/Control_Flow_Statements.rst
+++ b/source/Control_Flow_Statements.rst
@@ -145,9 +145,6 @@ Exercise
 search all positions of Ecor1 binding sites in dna_1
 
 ::
- 
-   import collections
-   RestrictEnzyme = collections.namedtuple("RestrictEnzyme", "name comment sequence cut end")
 
    ecor1 = ("EcoRI", "Ecoli restriction enzime I", "gaattc", 1, "sticky")