Page 174 - Computer Science V2.0 Class 11

Fig 7.12: Code Visualization through Python Tutor

To start visualization, we click the <Next> icon. On executing the 1st line of code, Python creates the list lst1
comprising values 30, 60, 10, 20, and 50 (Fig 7.13). The execution environment of Python script is called global frame.
So, the visualisation shows the list lst1 in the global frame. The left panel of the code box shows two arrows colored
in red and green respectively. While the green arrow refers to the line just executed, red arrow points to the next line
to be executed.

Fig 7.13: Code Visualization through Python Tutor (after execution of line 1)

As the red arrow points to line 2, clicking <Next> executes line 2. Now each of the two names (variables) lst1 and
lst2 refers to the same list (Fig 7.14). Note that the global frame now contains two entries, one for name lst1 and
another for lst2.

Fig 7.14: Code Visualization through Python Tutor (after execution of line 2)

160 Touchpad Computer Science (Ver. 2.0)-XI