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 = False
Code language: Python (python)

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

>>> 20 > 10 True >>> 20 < 10 False
Code language: Python (python)

Also, comparing two strings results in a boolean value:

>>> 'a' < 'b' True >>> 'a' > 'b' False
Code 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) False
Code 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.
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