This article demonstrates the different ways available to check if a variable is NULL in Python.
What is the NULL keyword?
The NULL keyword is a fundamental part of programming. Being used in all popular programming languages like C, C++, or Java, it can essentially be represented as a pointer that points to nothing, or it simply ascertains the fact that the given variable is vacant.
What is NULL in Python?
Python operates differently from the other popular programming languages. Python defines the NULL object with the None keyword instead. These NULL objects are not valued as 0 in Python though. It does not hold any value whatsoever. This None keyword in Python is both an object and a None type data type.
How to check if a variable is NULL in Python?
Using the is operator to check if a variable is NULL in Python.
We can simply use the is operator or the = operator to check if a variable is None in Python.
The following code uses the is operator to check if a variable is NULL in Python.
a = None
if a is None:
print('a is None')
else:
print('a is not None')
The above code provides the following output:
We have made use of the is operator in this code to check the condition. Alternatively, we can also make use of the == operator to complete this task.
The following code implements the same by utilizing the == operator.
a = 16
if a == None:
print('a is None')
else:
print('a is not None')
The above code provides the following output:
Using the if condition to check if a variable is NULL in Python.
We can simply use the if condition along with no additional operators in order to find out whether the given variable is None or not.
The following code uses the if condition to check if a variable is NULL in Python.
a = None
if a:
print('a is not None')
else:
print('a is None')
The above code provides the following output:
Using the not equal to operator to check if a variable is NULL in Python.
Another method to reveal whether a variable is None or not in Python is to utilize the != or the not equal to operator.
The following code uses the not equal to operator to check if a variable is NULL in Python.
a = None
if a != None:
print('a is not None')
else:
print('a is None')
The above code provides the following output:
These are the three methods that can be utilized to check whether the given variable is a None object or not.
Further, we can even check if the given variable is of the None data type as follows.
a = None print(type(a))
That’s all about how to check for null in Python.
