3.1. Booleans

A Boolean is another variable type (like integers, floats and string). A Boolean can be a True or a False.

x = True
y = False

print(type(x))

<class 'bool'>

True and False are keywords. They need to be capitalised. The following code will return a NameError. This is because Python doesn’t recognise true as a keyword (note it hasn’t turned purple). The program is looking for true to be defined somewhere in the code, but it can’t find it.

x = true

Computers store boolean values as 0’s or 1’s.

• 0 for False

• 1 for True

This means you can convert between booleans and integers. Have a look at the examples below.

print(int(True))

print(bool(0))

1
False

Booleans are also often used in datasets to represent categorical data with two options. Here is an example of a student attendance sheet.

Name	Attended
Alice	1
Bob	0
Charlie	1
David	1

1 indicates the student went to class and 0 indicates the student did not attend class.