In this blog, you will learn everything about the python NULL operator. We will understand how to use NULL in various situations. so let’s get started.
Basic of python null
In python, the NONE keyword is used to define the NULL values. There is no NULL object in python. The behavior of NULL in python differs from other programming languages like C, C++, or JAVA.
None in python
The NONE keyword is used to define NULL in python. In Python, the NONE keyword is not equal to 0 or an empty string or FALSE.NONE has its own data type which is NoneType.
We can allocate None to any variable, but you can not create NoneType objects.
In python, a function returns NONE when there is no return statement.
def empty_fun():
pass
print(empty_fun())The above code gives NONE as the output
Syntax of python NONE
The syntax of python NONE follows the below pattern.
NONEPython None vs NULL
In Python, None is an instance of the NoneType object. None has no object value in python.
On the other hand, there is no NULL in python. Users need to use NONE instead of null values.
Python null check
In this session, we will understand how to check if a value is NONE in python. Let’s understand this with the below example.
var = None
if var is None:
print("var is None")
else:
print("var is Not None")The above code prints “var is None”
since in python NONE keyword is used to represent NULL, so a user needs to compare a value with NONE.
Python null string
In this session, you will understand how to check if a string is NULL or NONE in python.
In python, string NONE and NONE objects are 2 different things you can not compare a sting NONE with a None object. It will always return the false as output.
Instead, you can check if a string is empty in python using the below code snipped.
str= ""
if (len(str)==0):
print("string is empty")
else:
print("string is not empty")The above code will print the “string is empty” as output.
Additional python null operations
In this session, we will understand how to use the Python NULL operator to perform various operations.
Python is null or empty
In python, NULL or empty can be checked using the python len() function. Below is the code snipped to check the null or empty in python.
var= " "
if (len(str.strip())==0):
print("empty")
else:
print("not empty")The strip() function is used along with the len() function to remove any blank spaces.
python if not null
In python, a variable that is not NULL can be checked using the is None method. Below is the code snipped to verify not NULL
var= "hello naiveskill"
if var is not None:
print(True)
else:
print(False)Since var is not null so we will get True as output.
