Boolean
Info:
In programming, you often want to check if a condition is true or not and to 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
- False
Note that True and False always start with capital letters.
The following example defines two boolean variables:
is_active = True
is_admin = False
For example when you compare two numbers, Python returns the result as a boolean value. For example:
>>> 20 > 20
True
>>> 20 < 10
False
Also comparing two strings results in a boolean value:
>>> 'a' < 'b'
True
>>> 'a' > 'b'
False
The bool() function:
To find out if a value is True or False, you can use the bool() function. For example:
>>> bool('Hi')
True
>>> bool('')
False
>>> bool(100)
True
>>> bool(0)
False
When a value evaluates to True, it's truthy. And if a value evaluates to False, it's falsy.
- The number zero ( 0 )
- An empty string ' '
- False
- None
- An empty list [ ]
- An empty tuple ( )
- An empty dictionary { }
All the other values that are NOT falsy are truthy values.
Most values are True
- Almost any value is evaluated to
Trueif it has some sort of content. - Any string is
True, except empty strings. - Any number is
True, except0. - Any list, tuple, set and dictionary are
True, except empty ones.
Examples:
The following will return True :
bool("abc")
bool(123)
bool(["apple", "cherry", "banana"])
Functions can return a value:
You can create functions that returns a Boolean value:
def myFunction() :
return True
print(myFunction())
So the function example above will return True.