Changed example of dict comprehension

ipynb/pres07_data_struct.ipynb

@@ -310,11 +310,11 @@
 ns.pop()
 ```
 
 %%%% Output: execute_result
 
-    3
+    12
 
 %% Cell type:markdown id: tags:
 
 ## Complity :
 
@@ -452,13 +452,14 @@
 ```
 
 %% Cell type:code id: tags:
 
 ``` python
-# dict comprehension (here for the "inversion" of the dictionary)
+# dict comprehension (here to change the case of values)
 print(d)
-d1 = {v: k for k, v in d.items()}
+d1 = {k: v.upper() for k, v in d.items()}
+print(d1)
 ```
 
 %% Cell type:markdown id: tags:
 
 ## Do it yourself: