TypeError: 'NoneType' object is not iterable

An iterable is a Python object that you can use as a sequence. You can go to the next item in the sequence using the next() method. This error means that Python is trying to iterate over a None object.

With Python, you can only iterate over an object if that object has a value. This is because iterable objects only have a next item which can be accessed if their value is not equal to None. If you try to iterate over a None object, you encounter the TypeError: 'NoneType' object is not iterable error. A None value is not iterable because it does not contain any objects. None represents a null value.

An Example Scenario:

Here, you can see that when try to iterate the list_items, the output is 'NoneType' object is not iterable because the list_items has the value of None.

Python object is not iterable

How to solve?

To solve this error, figure out where the variable got assigned a None value and correct the assignment or check if the variable doesn't store None before iterating.

Using type() method

You can easily avoid the NoneType exception by checking if a value is equal to None before you iterate over that value.

Using try-except

In some other cases, you can handling nonetype object with try-except.

Using isinstance()

You can use isinstance() function to check the type of iterable object.

Iterable objects

An iterable is a Python object that you can use as a sequence. Actually, String, List, and tuple are iterable objects. You need to make sure that before iterating these objects, it must not be empty. There is a difference between a None object and an empty iterable. This error is not raised if you have any empty list or a string.

__iter__ method

Python's interpreter converted your code to pyc bytecode. The Python virtual machine processed the bytecode, it encountered a looping construct which said iterate over a variable containing None. The operation was performed by invoking the __iter__ method on the None. None has no __iter__ method defined, so Python's virtual machine tells you what it sees: that NoneType has no __iter__ method.

What is NoneType?

In Python2, NoneType is the type of None.

In Python3, NoneType is the class of None.

Java or C++

Java or C++ doesn't have these problems because such a program wouldn't be allowed to compile since you haven't defined what to do when None occurs.

 (C) 2023    Founded by raps mk
All Rights Reserved. All other trademarks are property of their respective owners.
SiteMap  | Terms  | About