Typeerror object of type nonetype has no len

Want to know how to solve “Typeerror object of type nonetype has no len” error in Python?

Then, you are in the right place.

In this article, we will discuss the “Typeerror object of type nonetype has no len”, provide the possible causes of this error, and give solutions to resolve the error.

First, let us know what this error means.

What is Typeerror object of type nonetype has no len?

“Typeerror object of type nonetype has no len” is an error message in Python indicating that you are trying to call the len() function on an object that is NoneType.

Nonetype

In Python, NoneType is a special built-in constant that represents the absence of a value or a null value.

None is often used as a default value for function arguments.

It is a return value for functions that do not explicitly return anything.

len()

len() is a built-in function in Python that returns the number of items in an iterable object such as a string, list, tuple, dictionary, etc.

The function takes one argument, which is the iterable object whose length is to be calculated.

It returns an integer that represents the number of items in the iterable.

Several built-in functions in Python return None by default. Here’s an example:

my_var = None
print(len(my_var)) # returns None

In this example code, we are assigning the value None to the variable my_var.

When we then try to call the len() function on my_var, Python raises an error:

TypeError: object of type 'NoneType' has no len()

Because None does not have a length or size.

Let’s discuss further how this error occurs.

How does Typeerror object of type nonetype has no len occurs?

“Typeerror object of type nonetype has no len” error occurs when you try to call the len() function on an object that has a value of None.

This error usually occurs when you pass a None object to a function that expects an iterable or a sequence with a length such as a list, tuple, or string.

Here are the other reasons why this error occurs:

• When you assign the value None to a variable and later try to call the len() function on that variable:

my_var = None
print(len(my_var)) # TypeError: object of type 'NoneType' has no len()

In this example code, we assigns the value None to the variable my_var and then tries to call the len() function on my_var.

Since None is a special keyword in Python that represents the absence of a value, it cannot be measured in terms of its length or size.

Therefore, when we call the len() function on my_var, Python raises an error:

TypeError: object of type 'NoneType' has no len()

• When a function returns None by default or explicitly, and you try to call the len() function on the returned value:

def my_function():
    print("Hello, world!")

result = my_function()
print(len(result)) # TypeError: object of type 'NoneType' has no len()

In the above example, the my_function() function prints “Hello, world!” when called but does not return anything.

Therefore, when we call my_function() and assign the result to the variable result, we get None as the output because the function does not return anything explicitly.

Now let us know how to fix this error.

How to solve Typeerror object of type nonetype has no len?

Here are the alternative solutions that you can use to fix the Typeerror object of type nonetype has no len:

Solution 1: Check if the object is None before calling len():

Checking if the object is None before calling len() prevents the len() function from being called on a None object.

Just like the example below:

my_var = None

if my_var is not None:
    print(len(my_var))
else:
    print("Object is None.")

In the above example, we first check if the object my_var is not None before calling the len() function.

If my_var is not None, we call the len() function on my_var. Otherwise, we print the message:

Object is None.

Solution 2: Return a non-None object from a function:

It ensures that the object being passed to the len() function is not None and has a valid length or size.

For example:

def my_function():
    my_string = "Hello, world!"
    return my_string

result = my_function()
print(len(result))

In the above example, we define the my_function() function to return a non-None object (my_string).

We then call my_function() and assign the result to the variable result.

Finally, we call the len() function on result.

By following these solutions, you can fix the “Typeerror object of type nonetype has no len” error in your python code.

Here are the other fixed Python errors that you can visit, you might encounter them in the future.

• typeerror unsupported operand type s for str and int
• typeerror: object of type int64 is not json serializable
• typeerror: bad operand type for unary -: str

Conclusion

In conclusion, in this article, we discussed  “Typeerror object of type nonetype has no len”, provided its causes and give solutions that resolve the error.

By following the given solution, surely you can fix the error quickly and proceed to your coding project again.

I hope this article helps you to solve your problem regarding a Typeerror stating “object of type nonetype has no len”.

We’re happy to help you.

Happy coding! Have a Good day and God bless.