Edit exercise 4 to remove some pain-points for students

exercises.py

@@ -46,14 +46,18 @@ exercise.code = "weight = {}  #TODO: Initialise weight with correct values\navai
 exercise.tests = [Test("Weight calculation", "Overall weight: 310\n")]
 exercise.checks = [Check("You should use a for loop to loop over all keys in one of the dictionaries", "for "),
   Check("You should calculate the value", "310", True),
-  Check("You need to specify the correct weights in a dictionary", "[\"']pencil[\"']:(\\s)+10"),
-  Check("You need to specify the correct weights in a dictionary", "[\"']pen[\"']:(\\s)+20"),
-  Check("You need to specify the correct weights in a dictionary", "[\"']paper[\"']:(\\s)+4"),
-  Check("You need to specify the correct weights in a dictionary", "[\"']eraser[\"']:(\\s)+80"),
-  Check("You need to specify the correct availability in a dictionary", "[\"']pen[\"']:(\\s)+3"),
-  Check("You need to specify the correct availability in a dictionary", "[\"']pencil[\"']:(\\s)+5"),
-  Check("You need to specify the correct availability in a dictionary", "[\"']eraser[\"']:(\\s)+2"),
-  Check("You need to specify the correct availability in a dictionary", "[\"']paper[\"']:(\\s)+10")]
+  Check("For this exercise, you need to initialise the dicrionary when it is created", "\[[\"']pencil[\"']\](\\s)*=", True),
+  Check("For this exercise, you need to initialise the dicrionary when it is created", "\[[\"']pen[\"']\](\\s)*=", True),
+  Check("For this exercise, you need to initialise the dicrionary when it is created", "\[[\"']paper[\"']\](\\s)*=", True),
+  Check("For this exercise, you need to initialise the dicrionary when it is created", "\[[\"']eraser[\"']\](\\s)*=", True),
+  Check("You need to specify the correct weights in a dictionary", "[\"']pencil[\"'](\\s)*:(\\s)+10"),
+  Check("You need to specify the correct weights in a dictionary", "[\"']pen[\"'](\\s)*:(\\s)+20"),
+  Check("You need to specify the correct weights in a dictionary", "[\"']paper[\"'](\\s)*:(\\s)+4"),
+  Check("You need to specify the correct weights in a dictionary", "[\"']eraser[\"'](\\s)*:(\\s)+80"),
+  Check("You need to specify the correct availability in a dictionary", "[\"']pen[\"'](\\s)*:(\\s)+3"),
+  Check("You need to specify the correct availability in a dictionary", "[\"']pencil[\"'](\\s)*:(\\s)+5"),
+  Check("You need to specify the correct availability in a dictionary", "[\"']eraser[\"'](\\s)*:(\\s)+2"),
+  Check("You need to specify the correct availability in a dictionary", "[\"']paper[\"'](\\s)*:(\\s)+10")]
 exercises.append(exercise)
 
 # Exercise 5