Difference between != and is not operator in Python

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In this tutorial, let us look at the difference between != and is not operator in Python.

!= is defined in Python as the not equal to operator. If the operands on either side are not equal, it returns True; otherwise, it returns False.

The is not operator checks whether the id() of two objects is the same or not. If they are the same, it returns False; otherwise, it returns True. And the is not operator returns True if the operands on either side are not equal, and False if they are.

Difference between != and is not operator in Python

Method #1: Using is not Operator on Numbers

Approach:

  • Give the first number as static input and store it in a variable.
  • Give the second number as static input and store it in another variable.
  • Check if both the given numbers are equal or not using the is not operator.
  • Print the id of both the given numbers using the id() function.
  • The Exit of the Program.

Below is the implementation:

# Give the first number as static input and store it in a variable.
gvn_num1 = 5
# Give the second number as static input and store it in another variable.
gvn_num2 = 5

# Check if both the given numbers are equal or not using the is not operator
print(gvn_num1 is not gvn_num2)
# Print the id of both the given numbers using the id() function
print(id(gvn_num1), id(gvn_num2))

Output:

False
11256192 11256192

Explanation:

Here it returns the output as False since both variables
gvn_num1 and gvn_num2 referred to the same data 5

Method #2: Using is not Operator on Strings

Approach:

  • Give the first string as static input and store it in a variable.
  • Give the second string as static input and store it in another variable.
  • Check if both the given strings are equal using the is not operator.
  • Print the id of both the given strings using the id() function.
  • The Exit of the Program.

Below is the implementation:

# Give the first string as static input and store it in a variable.
gvn_str1 = "pythonprogarms"
# Give the second string as static input and store it in another variable.
gvn_str2 = "pythonprogarms"

# Check if both the given strings are equal using the is not operator
print(gvn_str1 is not gvn_str2)
# Print the id of both the given strings using the id() function
print(id(gvn_str1), id(gvn_str2))

Output:

False
140627397413232 140627397413232

Explanation:

Here it returns the output as False since both the string variables
gvn_str1 and gvn_str2 referred to the same data "pythonprogarms"

Method #3: Using is not Operator on Lists

# Give the first list as static input and store it in a variable.
gvn_lst1 = [10, 15, 20]
# Give the second list as static input and store it in another variable.
gvn_lst2 = [10, 15, 20]

# Check if both the given lists are equal using the is not operator
print(gvn_lst1 is not gvn_lst2)
# Print the id of both the given lists using the id() function
print(id(gvn_lst1), id(gvn_lst2))

Output:

True
140627403656880 140627397425344

Explanation:

Here it returns the output as True since both the variables
gvn_lst1 and gvn_lst2 have distinct memory addresses even if 
both variables contain the same data.

Method #4: Using != Operators on Numbers

Approach:

  • Give the first number as static input and store it in a variable.
  • Give the second number as static input and store it in another variable.
  • Check if both the given numbers are equal or not using the != operator.
  • Print the id of both the given numbers using the id() function.
  • The Exit of the Program.

Below is the implementation:

# Give the first number as static input and store it in a variable.
gvn_num1 = 5
# Give the second number as static input and store it in another variable.
gvn_num2 = 5

# Check if both the given numbers are equal or not using the != operator
print(gvn_num1 != gvn_num2)
# Print the id of both the given numbers using the id() function
print(id(gvn_num1), id(gvn_num2))

Output:

False
11256192 11256192

Method #5: Using != Operators on Strings

Approach:

  • Give the first string as static input and store it in a variable.
  • Give the second string as static input and store it in another variable.
  • Check if both the given strings are equal or not using the != operator.
  • Print the id of both the given strings using the id() function.
  • The Exit of the Program.

Below is the implementation:

# Give the first string as static input and store it in a variable.
gvn_str1 = "pythonprogarms"
# Give the second string as static input and store it in another variable.
gvn_str2 = "pythonprogarms"

# Check if both the given strings are equal or not using the != operator
print(gvn_str1 !=  gvn_str2)
# Print the id of both the given strings using the id() function
print(id(gvn_str1), id(gvn_str2))

Output:

False
140627397413232 140627397413232

Method #6: Using != Operators on Lists

# Give the first list as static input and store it in a variable.
gvn_lst1 = [10, 15, 20]
# Give the second list as static input and store it in another variable.
gvn_lst2 = [10, 15, 20]

# Check if both the given lists are equal or not using the !=  operator
print(gvn_lst1 != gvn_lst2)
# Print the id of both the given lists using the id() function
print(id(gvn_lst1), id(gvn_lst2))

Output:

False
140627397115488 140627397114768

Method #7: Comparing != and is not operators

gvn_lst1 = []
gvn_lst2 = []
gvn_lst3 = gvn_lst1

# Applying != operator for comparing gvn_lst1 and gvn_lst2
if (gvn_lst1 != gvn_lst2):
    print("True")
else:
    print("False")
 
# Applying is not operator for comparing gvn_lst1 and gvn_lst2
if (gvn_lst1 is not gvn_lst2):
    print("True")
else:
    print("False")
    
# Applying is not operator for comparing gvn_lst1 and gvn_lst3
if (gvn_lst1 is not gvn_lst3):
    print("True")
else:
    print("False")

# Concatenating given third and secondlists and saving it as a given third list
gvn_lst3 = gvn_lst3 + gvn_lst2

# Applying is not operator for comparing gvn_lst1 and gvn_lst3
if (gvn_lst1 is not gvn_lst3):
    print("True")
else:
    print("False")

Output:

False
True
False
True

Explanation:

  • Because both gvn_lst1 and gvn_lst2 are empty lists, the output of the first condition is “False”.
  • Second, if the condition is “True,” it means that two empty lists are located in different memory locations. As a result, gvn_lst1 and gvn_lst2 correspond to distinct items. We can test it using Python’s id() function, which returns an object’s “identity.”
  • If the condition is “False,” the output of the third is “False,” because both gvn_lst1 and gvn_lst3 point to the same object.
  • Since the concatenation of two lists always produces a new list, the output of the fourth if the condition is “True.”