The bool() in python returns a boolean value of the parameter supplied to it. The parameter can be any of the following and the results are as per the below conditions. Except the values mentioned here the remaining values return True.
False is returned when the parameter value passed is as below −
None
A False condition
Zero of any numeric type
Empty sequence (), [] etc.
Empty mapping like {}
objects of Classes which has __bool__() or __len()__ method which returns 0 or False
Example
In the below program, we illustrate all such example scenarios.
print("None gives : ",bool(None))
print("True gives : ",bool(True))
print("Zero gives: ",bool(0))
# Expression evaluating to true
print("Expression evaluating to True: ",bool(0 == (18/3)))
# Expression evaluating to false
print("Expression evaluating to False: ",bool(0 == (18%3)))
s = ()
print("An mpty sequence: ",bool(s))
m = {}
print("An emty mapping: ",bool(m))
t = 'Tutoriaslpoint'
print("A non empty string: ",bool(t))Output
Running the above code gives us the following result −
None gives : False True gives : True Zero gives: False Expression evaluating to True: False Expression evaluating to False: True An mpty sequence: False An emty mapping: False A non empty string: True