1. Creating Maintainable code
Learning Python
Creating Maintainable code

2. Code Maintainability
Always try to make any code that you write is easy to read and understand
This benefits you and anyone else who reads your code
When you go back after a short time its easy to forget exactly why you wrote the code the way you did
You should apply good readability principles to pseudocode and real code

3. Good Techniques - 1 At the beginning of the code include :
Your Name
Date
Purpose
Use descriptive names for variables eg userChoice instead of num
Add blank lines between different block of code
Add comments that explain what each part of the code does
You can over comment
Commenting each line is unnecessary and makes the code less readable

4. Good techniques - 2 Technique Description Comments
Comments should be used to:
Who wrote the code
Date of writing
Explain the purpose of the program
Explain what each part does
Explain any part where logic or setting variables is difficult to understand
Descriptive Names
Using descriptive identifiers for variables, constants and functions helps to make their purpose clear
Use camel case for multi-word names eg firstName, totalScore
Indentation
Indentation makes it clear where each block of code starts and finishes. Getting this wrong can result in the program not running or producing incorrect results
White space
Spaces between
Assignment operators and values
Selection tests
Blank lines between different blocks of code to make them stand out :
If blocks
While and For loops

5. Use the Python comment character # to start your comments
Exercise 1
Rewrite this algorithm using appropriate techniques to make it easier to read: Set X to 10 While X >= 0 Do If X > Print (X) Else Print(“Blast Off”) End If X = X -1 End While
Use the Python comment character # to start your comments

6. Exercise 1 - Solution
# Name: your name # Date: Today’s date # Purpose: Count down from and display a message #initialise variables counter = 10 While counter >= 0 Do If counter > Print (counter) Else Print(“Blast Off”) End If counter = counter -1 End While

7. Exercise 2 – Improve this code