Programming Principles (Python)

Introduction

The assignment entailed using the python Turtle library to draw an interactive forest simulation application. Turtle is a graphics library in python that allows drawing of images of the canvas(Vidal,2016). The application should allow the user to draw in different positions of the screen, either bird icons or tree icons. This is done when they choose the kind of image they want, e.g. bird and click at the position.

Prerequisites

The implementation of the project has prerequisites which must be met for it to work as expected.

One of them is a Python programming language installation. Python is easy to learn a high-level programming language(Srinath,2017). This can be found at Python official website at www.python.org.

You also need the Python Turtle module. These can be installed using the Python Package Manager called Pip or Pip3 for Python version 3. A package manager is a command that enables users to install and manage packages written by other programmers in a particular programming language(Muhammad et al.,2019). The Turtle Package can be installed with the command:

python3 -m pip install PythonTurtle

Design

The project was designed using a top-down approach. This involved decomposing the program into smaller, manageable functions and objects. The program was first divided into two classes to be implemented, Draw for drawing the tree and bird icons, and Forest, which finally achieved the forest simulation functionality. The classes were further decomposed into different methods and properties which carried out different feature. This made development easier since you could focus on one function at a time without worrying about other parts of the program(Goschnick,2018).

Different design techniques were also applied. Most outstanding of them was the use of flowcharts in the design of some of the functions that were employed in the program. A flowchart is a pictorial model of how program execution should start, proceed and end(Herrera-Camara,2017). The following is a flowchart for the handle_click() function that was implemented in the program.

Testing

Testing is essential in software development to eliminate errors and failures that could be caused by the program. It also assures users that the program is working as expected.

Several test cases were developed to test the program functionality.

Test Data Table
Test data type	Test data	The reason it was selected	The output expected due to the use of the test data	The screenshot of actual output when the test data is used
Normal	User clicks inside boundary margins	To show that either tree or bird icon is displayed	Either tree or bird icon is displayed
Normal	User clicks on tree’s circle	To show that turtle changes to a tree	Clicking inside boundary displays tree icon.
Normal	User clicks on bird’s circle	To show that turtle changes to bird	Clicking inside boundary displays bird icon
Normal	User clicks left arrow keyboard key when bird icon selected	To show that the angle of the turtle changes	The angle of turtle icon changes anti-clockwise
Abnormal	User clicks on “up” keyboard key	To show that the “up” keyboard key does not change application state	No action is undertaken.
Abnormal	User clicks on “b” keyboard key	To show that the “b” keyboard key does not change application state	No action is undertaken.
Abnormal	User clicks outside boundary margins	To show that clicking outside boundary margins does not initiate action	No action is undertaken.

Conclusion

The program was implemented successfully using the Python3 programming language. All the objectives were also met.

References

Vidal Duarte, E. (2016, July). Teaching the First Programming Course with Python’s Turtle Graphic Library. In Proceedings of the 2016 ACM Conference on Innovation and Technology in Computer Science Education (pp. 244-245).

Srinath, K. R. (2017). Python–The Fastest Growing Programming Language. International Research Journal of Engineering and Technology (IRJET), 4(12), 354-357.

Muhammad, H., Real, L. C. V., & Homer, M. (2019, October). Taxonomy of Package Management in Programming Languages and Operating Systems. In Proceedings of the 10th Workshop on Programming Languages and Operating Systems (pp. 60-66).

Goschnick, S. (2018). A Design Method for People-Oriented Programming.

Herrera-Camara, J. I., & Hammond, T. (2017, July). Flow2Code: from hand-drawn flowcharts to code execution. In Proceedings of the Symposium on Sketch-Based Interfaces and Modeling (pp. 1-13).