PYTHON DICTIONARY

Comments

Data types

Variables

If Else

​​​If Elif Else

Functions

For loop

While loop

Data structures

String slicing/indexing

User defined function

Local/Global variable

Validation and Try

Methods

File I/O

Pseudocode

Modules​

What is validation?

Validation is the automatic checking of entered data by a computer program. Validation cannot check that the data entered is correct only that it is a reasonable value or has been entered at all. 
Enter and run the following code and instead of entering your name, just hit enter with nothing entered. What happens? How can you edit the code to accept a minimum of 3 characters entered? This particular validation is called a presence check i.e. has the user entered anything at all or just pressed enter. As soon as you change the value  of "len" from zero to anything above zero, it stops being a presence check and becomes a length check.

Validation - Range check
Enter the following code in a Python code editor. Before running the code, what do you think it will do? Press "F5" then "Enter" to run
Most cars only have 4 tyres. This means that the range of tyres that can be changed on a car is 1 to 4. What happens if you want to change 0 tyres or more than 4 tyres?

Validation - Lookup check

What happens if you choose something not in the list called "allTitles"?

Python challenge - Try

Enter the following code in a Python code editor. Before running the code, what do you think it will do? Press "F5" then "Enter" to run
In this code, the third line specifies that a user enters an INT. Run the code and enter some letters instead. Will the code crash? Depending if the data entered by the user, the code will branch accordingly and ultimately prevent your code from crashing.

​Python challenge - Try - Zero division error

Enter the following code in a Python code editor. Before running the code, what do you think it will do? Press "F5" then "Enter" to run
In this code you are handling an exemption. The exemption is a user attempting to divide by zero. Can you add additional code that occurs after the exception that redirects a user to to perform a division again?

Python challenge - email validation

Enter the following code in a Python code editor. Before running the code, what do you think it will do? Press "F5" then "Enter" to run
This is a basic form of validation to see if a particular character exists in a users input. For instance, if a user is asked to enter their email address and they type in some gibberish, you can create some code that validates and rejects it.