Python | Check If A Given Object Is A List Or Not

Given an object, the task is to check whether the object is a list or not. Python provides few simple methods to do this and in this article, we'll walk through the different ways to check if an object is a list:

Using isinstance()

isinstance() function checks if an object is an instance of a specific class or data type.

if isinstance([1, 2, 3], list):
    print("Object is a list")
else:
    print("Object is not a list")
if isinstance("12345", list):
    print("Object is a list")
else:
    print("Object is not a list")

Object is a list
Object is not a list

Explanation:isinstance(obj, list) returns True if obj is a and False if it's not.

Using type()

Another method to check if an object is a list is by using the type() function. This function returns the exact type of an object.

l1 = [1, 2, 3]
l2 = (10, 20, 30)  # A tuple
if type(l1) is list:
    print("Object is a list")
else:
    print("Object is not a list")
if type(l2) is list:
    print("Object is a list")
else:
    print("Object is not a list")

Object is a list
Object is not a list

Explanation:

• type(obj) returns the exact type (e.g., list, tuple, dict).
• Unlike isinstance(), it does not consider inheritance, useful when strict type matching is needed.

Using __class__ Attribute

To check if an object is a list , we can use the __class__ attribute and compare it to the list type:

l1 = [1, 2, 3, 4, 5]
l2 = (12, 22, 33)
if l1.__class__ == list:
    print("input is a list")
else:
    print("input is not a list")
if l2.__class__ == list:
    print("input is a list")
else:
    print("input is not a list")

input is a list
input is not a list

Explanation:

• __class__ returns the class of an object.
• While it works, it’s less readable and not as commonly used as isinstance().