Python Boolean

Summary: in this tutorial, you’ll learn about the Python boolean data type, falsy and truthy values.

Introduction to Python Boolean data type

In programming, you often want to check if a condition is true or not and perform some actions based on the result.

To represent true and false, Python provides you with the boolean data type. The boolean value has a technical name as bool.

The boolean data type has two values: True and False.

Note that the boolean values True and False start with the capital letters (T) and (F).

The following example defines two boolean variables:

is_active = True
is_admin = FalseCode language: Python (python)

When you compare two numbers, Python returns the result as a boolean value. For example:

>>> 20 > 10
True
>>> 20 < 10
FalseCode language: Python (python)

Also, comparing two strings results in a boolean value:

>>> 'a' < 'b'
True
>>> 'a' > 'b'
FalseCode language: Python (python)

The bool() function

To find out if a value is True or False, you use the bool() function. For example:

>>> bool('Hi')
True
>>> bool('')
False
>>> bool(100)
True
>>> bool(0)
FalseCode language: Python (python)

As you can see clearly from the output, some values evaluate to True and the others evaluate to False.

Falsy and Truthy values

When a value evaluates to True, it’s truthy. And if a value evaluates to False, it’s falsy.

The following are falsy values in Python:

• The number zero (0)
• An empty string ''
• False
• None
• An empty list []
• An empty tuple ()
• An empty dictionary {}

The truthy values are the other values that aren’t falsy.

Note that you’ll learn more about the None, list, tuple, and dictionary in the upcoming tutorials.

Summary

• Python boolean data type has two values: True and False.
• Use the bool() function to test if a value is True or False.
• The falsy values evaluate to False while the truthy values evaluate to True.
• Falsy values are the number zero, an empty string, False, None, an empty list, an empty tuple, and an empty dictionary. Truthy values are the values that are not falsy.