Python - Datatype - None & Boolean Tutorial

None Datatype

None Keyword is used to define null value. It is a datatype of class 'NoneType' Object. It is not the same as Zero, False, or an empty String.

For example-

x=None
y=None

print(type(x))
print(type(y))

print(id(x))
print(id(y))

Output-

<class 'NoneType'>
<class 'NoneType'>
139650864453248
139650864453248

When we assign a variable with a value None, we are resetting the variable to its original state. Any variable assigned with a value None will have the same identity, i.e they point to the same object.

Boolean Datatype

Boolean Datatype is used to define the truth value of an expression. It is represented with one of the two values i.e True or False. We can evaluate values and expressions using the python bool() function.

False & True is a datatype of class bool.

print('Printing type of False & True')
f1=False
t1=True
print(type(f1))
print(type(t1))

Output-

Printing type of False & True
<class 'bool'>
<class 'bool'

Condition on which variable of a different datatype is represented as True or False.

• In integer 0 is False, rest all integer value is True
• In float 0.0 is False, rest all float value is True
• In String, only empty string is False
• In complex 0+0j is False, rest all complex value is True
• Variable with value None is also a False
• Empty List, empty tuple, empty dictionary, empty set are false and rest all are True

For example-

print('Value whose boolean type is False')
f1=None
f2=0
f3=0.0
f4=""
f5=0+0j

print(bool(f1))
print(bool(f2))
print(bool(f3))
print(bool(f4))
print(bool(f5))

print('Value whose boolean type is True')
#In integer 0 is False, rest all integer value is True
t1=-1
t2=2

#In float 0.0 is False, rest all float value is True
t3=3.4

#In String , only empty string is False
t4='fresherbell'

#In complex 0+0j is False, rest all complex value is True
t5=0+3j
t6=1+5j

print(bool(t1))
print(bool(t2))
print(bool(t3))
print(bool(t4))
print(bool(t5))
print(bool(t6))

Output-

Value whose boolean type is False
False
False
False
False
False
Value whose boolean type is True
True
True
True
True
True
True