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:
x = 20
y = 10
result = x > y
print(result)
result = x < y
print(result)Code language: Python (python)Output:
True
FalseCode language: PHP (php)Also, comparing two strings results in a boolean value:
x = 'a'
y = 'b'
result = x > y
print(result)
result = x < y
print(result)Code language: Python (python)Output:
False
TrueCode language: PHP (php)The bool() function #
To find out if a value is True or False, you use the bool() function. For example:
result = bool('Hi')
print(result)
result = bool(100)
print(result)
result = bool(0)
print(result)Code language: Python (python)Output:
True
True
FalseCode language: PHP (php)The output indicates some values evaluate to True and the others evaluate to False.
Falsy and Truthy values #
When a value evaluates to True, it’s truthy. If a value evaluates to False, it’s falsy.
The following are falsy values in Python:
- The number zero (
0) - An empty string
'' FalseNone- 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:
TrueandFalse. - Use the
bool()function to test if a value isTrueorFalse. - Falsy values evaluate to
Falsewhereas truthy values evaluate toTrue. - Flasy 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.