1.13 Itse1359-1065-visualizing python

Table of contents

• Preface
  • Viewing tip
    • Figures
    • Listings
• General background information
• Recommendation
• Discussion and sample code
  • Open the online text editor
  • Three drop-down boxes
  • Beginning the visualization process
  • The red and green arrows
  • Output following three presses of the Forward button
  • Same situation, different code
  • Stepping through the code
  • The student torture program
  • Sharing the code visualizer with a tutor
• Run the programs
• Miscellaneous

Preface

This module is one in a collection of modules on Python designed for teaching ITSE 1359 Introduction to Scripting Languages: Python at Austin Community College in Austin, TX. This module concentrates on the use of the Online Python Tutor , which includes a free educational code visualizer tool created by Philip Guo .

This code visualizer tool helps students overcome a fundamental barrier to learning programming: understanding what happens as the computer executes eachline of a program's source code. Using this code visualizer tool, a teacher or student can write Python, Java, and JavaScript programs in the Web browser andvisualize what the computer is doing step-by-step as it executes those programs.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figuresand Listings while you are reading about them.

Figures

• Figure 1. The online text editor.
• Figure 2. Beginning the visualization process.
• Figure 3. Output following three presses of the Forward button.
• Figure 4. Same situation, different code.
• Figure 5. The student torture program.

Listings

• Listing 1. A sample program with proper indentation.
• Listing 2. Another sample program with proper indentation.

General background information

I touched on the use of the code visualizer in the earlier module titled Itse1359-1050-Introduction to Scripts . I also touched on the code visualizer in the module titled Itse1359-2510-Getting Started with the Online Python Tutor Code Visualizer in this book . The purpose of this module is to provide additional information related to the codevisualizer.

When learning to program, it is often useful to be able to follow the execution of a program step-by-step. A free online tool called the Online Python Tutor makes this possible. The following quotation was copied from pythontutor.com .

" Online Python Tutor is a free educational tool created by Philip Guo that helps students overcome a fundamental barrier to learning programming:understanding what happens as the computer executes each line of a program's source code. Using this tool, a teacher or student can write Python , Java , and JavaScript programs in the Web browser and visualize what the computer is doingstep-by-step as it executes those programs."

Recommendation

I recommend that from this point forward in this course, you copy and paste every sample program into the code visualizer and observe the behavior ofthat code as you step through the program, one instruction at a time. I believe that doing that will help you to better understand Python programming.