Are you getting the “TypeError unsupported operand type s for NoneType and int” error while coding in Python?
Don’t worry, in this article, we will explain to you what this error means, and its causes.
How you can solve it with the solutions we provided.
What is TypeError: unsupported operand type(s) for NoneType and int Error?
This error usually occurs when you are trying to perform an operation that involves NoneType and an integer data type.
In other words, this error occurs if you are attempting to do arithmetic operations on NoneType (a value that represents the absence of a value) and an integer.
This is an example of why this error occurs:
x = None
y = 5
result = x + yThis code will result in the following error message:
C:\Users\Dell\PycharmProjects\pythonProject\venv\Scripts\python.exe C:\Users\Dell\PycharmProjects\pythonProject\main.py
Traceback (most recent call last):
File “C:\Users\Dell\PycharmProjects\pythonProject\main.py”, line 3, in
result = x + y
TypeError: unsupported operand type(s) for +: ‘NoneType’ and ‘int’
In this example, this error message shows that the ‘+’ operator cannot be applied to the NoneType and int data types.
Causes of the Error
There are multiple reasons why you might encounter the unsupported operand type(s) for NoneType and int error while coding in Python.
Here are some common causes:
- You are using a NoneType value in an arithmetic operation.
- Not returning a value from a function.
- It might possible you are using the wrong data type.
- Not initializing a variable.
- You are using the wrong variable name.
Also, you read the other fixed python error that you might encounter when you run the python program.
- typeerror: loaderutils.getoptions is not a function
- Typeerror unsupported operand type s for dict and dict [SOLVED]
- Attributeerror module tensorflow compat v1 has no attribute contrib
How to solve this error?
To solve this error, you will make sure that the objects you are working with have the correct types.
In the example above, we could solve the issue through assigning a value to x that is not None:
x = 3
y = 5
result = x + y
print(result)Output:
C:\Users\Dell\PycharmProjects\pythonProject\venv\Scripts\python.exe C:\Users\Dell\PycharmProjects\pythonProject\main.py
8
This code defines two variables x and y and assigns them the values 3 and 5 respectively.
Then, the code calculates the sum of x and y using the “+ ” operator and assigns the result to a new variable named “result“.
Finally, the code prints the value of result using the print() function.
In this case, the value of result is 8, which is the sum of x and y.
How to Avoid the TypeError: Unsupported Operand Type(s) for NoneType and Int?
To avoid this error, you will make sure to always check the type of the objects you are working with.
Before you perform an operations on them.
It will be done using the type() function.
The other way to avoid this error is to make sure that your functions always return a value of the correct type.
If a function does not return anything, you can use the return None statement at the end of the function.
FAQs
A NoneType object represents the absence of a value.
No, NoneType objects cannot be concatenated with other data types in Python.
Frequently Asked Questions
What is Python TypeError and what causes it?
TypeError is raised when an operation is applied to an object of the wrong type. Common patterns: calling a non-callable object, adding incompatible types (str + int), passing the wrong number of arguments, or accessing attributes on a NoneType. Each TypeError message names the operation and expected vs actual types, the fix is almost always to convert types explicitly (int(), str()) or fix the wrong variable assignment.
How do I quickly debug a Python TypeError?
Three steps: (1) Read the full error message, it names the exact operation and types involved. (2) Print the type of every variable in that line: print(type(var1), type(var2)). (3) Check what the function expected vs what you passed. Most TypeError fixes are 1-line type casts or fixing a variable that became None unexpectedly.
Should I catch TypeError or let it propagate?
For internal code, let TypeError propagate, it’s almost always a real bug (wrong type passed). For boundary code (parsing user input, third-party API responses), catch TypeError + ValueError together: try: parsed = int(value) except (TypeError, ValueError): parsed = 0. Catching internal TypeErrors hides bugs.
How do I prevent TypeError in production?
Three patterns: (1) Use type hints (def add(a: int, b: int) -> int) and check with mypy / pyright in CI. (2) Validate inputs at boundaries (Pydantic for FastAPI, DRF serializers for Django). (3) Default values that match expected types (return 0 not None for numeric functions). Static typing catches 80% of TypeErrors before runtime.
Where can I find more TypeError fixes?
Browse the TypeError reference hub for 220+ specific TypeError fixes. For broader Python debugging, see the Python Tutorial hub. For related error types, see ValueError and AttributeError guides.
Conclusion
In this article, we’ve discussed the causes of the error, and what error means, and also we provide the solutions on how to solve it.
Through following these solutions, you can prevent encountering this error and you can run your python code smoothly.
Adones Evangelista
Programmer & Technical Writer at PIES IT Solution
Adones Evangelista is a programmer and writer at PIES IT Solution, author of over 900 tutorials and error-fix guides at itsourcecode.com. Specializes in JavaScript, Django, Laravel, and Python error debugging covering ValueError, TypeError, AttributeError, ModuleNotFoundError, and RuntimeError, plus C/C++ and PHP capstone projects for BSIT students.
Expertise: JavaScript · Python · Django · Laravel · Error Debugging · C/C++ · View all posts by Adones Evangelista →