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Same situation, different code

Figure 4 shows the same situation using the code from Listing 2. instead of the code from Listing 1 .

Figure 4. Same situation, different code.

missing image

Note that the values stored in the variables named A and B were reversed relative to the code in Figure 3 . As a result, the if statement pointed to by the green arrow returned false instead of true when that statement was executed. Because of that, execution ofthe indented code block following the if statement will be skipped entirely and the red arrow now points to the statement immediately following that code block.That is the next statement that will be executed.

Stepping through the code

As you use the Forward and Back buttons to step through the code, one instruction at a time, you can observe the red and green arrows to gain a betterunderstanding of the flow of control through the program. (You will learn more aboutflow of control in future modules and you will probably find that the code visualizer is particularly useful when analyzing that code.)

If you are in a hurry, you can press the First button and the Last button to cause the code visualizer to go the first or last instruction in one step.

The student torture program

There are links to quite a few sample programs below the drop-down boxes shown in Figure 1 . (I cropped them out of Figure 1 to save space.) One of those sample programs is named student torture .

As a preview of things to come, Figure 5 shows the result of opening that program in the code visualizer and pressing the Last button.

Figure 5. The student torture program.

missing image

Sharing the code visualizer with a tutor

Finally, there is another interesting sample program at (External Link) that you can step through and observe its behavior. While you are there, be sure to note your ability to share the code visualizer with a friend or a tutor on anothercomputer on the Internet and jointly analyze a program.

Run the programs

I encourage you to use the code in Listing 1 and Listing 2. along with the code visualizer to repeat theprocedures explained in this module. Confirm that you get results similar to those shown in Figure 3 and Figure 4 .

Change the options in the drop-down boxes and observe the results.

Experiment with the code, making changes, and observing the results of your changes. Make certain that youcan explain why your changes behave as they do.

As mentioned earlier, I strongly recommend that from this point forward in this course, you copy and paste every sample program into the code visualizerand observe the behavior of that code as you step through the program, one instruction at a time. I believe that doing that will help you to betterunderstand Python programming.


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Itse1359-1065-Visualizing Python
  • File: Itse1359-1065.htm
  • Published: 01/31/16

Financial : Although the Connexions site makes it possible for you to download a PDF file for thismodule at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, you should beaware that some of the HTML elements in this module may not translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.


Questions & Answers

how can chip be made from sand
Eke Reply
are nano particles real
Missy Reply
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
has a lot of application modern world
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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