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Python Booleans: True or False With Examples

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Boolean means Binary value. It only represents two values either 0 or 1. 1 means True and 0 means False. In any programming language, it is necessary to know which statement is true and which statement is false. It is basically used in conditional statements.

Boolean Values

In Python, we can evaluate a statement and get the result in Boolean format. Python will show the output when we compare two variables. Examples are given below,

print(5 > 3) #This will return True

print(4 == 7) #This will return False

print(1 < 11) #This will return True

When we run conditional statements, based on the Boolean value it works. For example,

x = 20

y = 30

if y > x: # if this statement is true

    print("y is greater than x") # This line will be printed

else: # if this statement is false

            print("x is not greater than x") # This line will not be printed

Python bool()

The bool method to change or return a value to Boolean. This method works using the standard truth testing procedure. The syntax of this bool method is bool([value]) i.e. bool[a]. The standard truth testing procedure will be applied if the method takes only one parameter. By default, this method will return False. This method has only two rules. Those are

  • If the parameter is false, it returns false
  • If the parameter is true, it returns true

Evaluate values and variables:

The method permits us to evaluate any value and returns the output in Boolean format. An example is given below

print(bool("Programming"))

print(bool(20))

#the above two statements return true

We can do the same task above by using variables. For example –

a= "Programming"

b= 20

print(bool(a))

print(bool(b))

#the above two statements return true

There are various conditions where bool() retunes true. Those are given below

  • If the value has some contents then it returns true
  • Without empty strings, it will return true
  • Without 0, it will return true
  • Without an empty list, tuple, set, and dictionary, it will return true

There are various conditions where bool() retunes false. Those are given below

  • For false parameter
  • For none parameter
  • For an empty sequence like (), [], etc.
  • For Zero parameter like 0, 0.0 etc.
  • For an empty mapping like {}
  • For __bool__() or __len()__ method

Complete Example of how bool Works :

a = False

print(bool(a)) # this will return False as a is False

a = True

print(bool(a)) # this will return True as a is True

a=bool(["apple", "cherry", "banana"])

print(bool(a)) # this will return True as a is True

a = 3

b = 7

print(bool(a==b)) # this will return False as a is not equal to b

a = None

print(bool(a)) # this will return False as a is None

a = ()

print(bool(a)) # this will return False as a is an empty sequence

a = {}

print(bool(a)) # this will return False as a is an empty mapping

a = 0.0

print(bool(a)) # this will return False as a is 0

a = “Python”

print(bool(a)) # this will returns True as a is a non-empty string

Boolean Object and Function

If we have an object and that object is made from a class with a __len__ function, then it returns False. An example is given below,

class pythonclass():

  def __len__(self):

    return 0

myclassobject = pythonclass()

print(bool(myclassobject))

#this will return false

The function also can return a Boolean value. Two functions are given below as an example,

def Function1() :

  return True

print(Function1())

#This will return True

def Function2() :

  return False

if Function2():

  print("Yes")

else:

  print("no")

#This will print no because the return false
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