What is the difference between classmethod and staticmethod?

Q: What is the difference between classmethod and staticmethod?

**Target Audience:** Beginners who know what `self` is, up to intermediate developers preparing for Python interviews. **Difficulty:** Medium **Python version:** Behaviour checked on CPython 3.11 and 3.13 (identical output except where a version is named); every in-page example also runs on Pyodide 0.25.1 (CPython 3.11.3). > **How to read this doc:** Each idea is explained in plain language first. When a word appears that an interviewer expects you to know, it is tagged with `📌 Interview term:` and defined right there. All of them are collected in the Quick Glossary at the end. Every output shown was produced by actually running the code. ## 1. Why This Even Matters — A Story First Picture a car factory with three kinds of workers. A **mechanic** works on one specific car: "fix the brakes on *this* car". They need the car in front of them. That is an ordinary method — it gets `self`. A **production planner** works on the *model line*: "build me a new car of this model from this o

The problem

Question presented to candidate: "Python has @classmethod and @staticmethod. What is the difference between them and a normal method, when would you reach for each, and what actually happens when you call one?"

What a strong answer should cover:

A normal method receives the instance (self), a class method receives the class (cls), a static method receives nothing extra — it is a plain function namespaced in the class.
Class methods are the tool for alternative constructors (dict.fromkeys, datetime.fromtimestamp) because cls(...) builds the subclass when called on a subclass; a static method has to hard-code the class.
Both can be called on the class or an instance; a class method called through an instance still gets the class.
Mechanism: both are descriptors stored in the class __dict__; classmethod.__get__ returns a method bound to the class, staticmethod.__get__ returns the underlying function unchanged.
Version facts: since Python 3.10 a staticmethod object is itself callable and both expose __wrapped__; chaining @classmethod over @property was deprecated in 3.11 and removed in 3.13.
Choosing: use a static method for a helper that needs neither the instance nor the class (or a module-level function), a class method when the class itself matters.

Code / implementation expected: Yes — a class with all three method kinds, an alternative constructor via @classmethod, and a subclass showing the difference.

classmethod
staticmethod

Try it yourself

Sketch your approach before you read the solution. That is what the interview tests.

Stuck? Get a hint.

A short nudge toward the approach. It will not give the answer away.

Solution

Target Audience: Beginners who know what self is, up to intermediate developers preparing for Python interviews. Difficulty: Medium Python version: Behaviour checked on CPython 3.11 and 3.13 (identical output except where a version is named); every in-page example also runs on Pyodide 0.25.1 (CPython 3.11.3).

How to read this doc: Each idea is explained in plain language first. When a word appears that an interviewer expects you to know, it is tagged with 📌 Interview term: and defined right there. All of them are collected in the Quick Glossary at the end. Every output shown was produced by actually running the code.

1. Why This Even Matters — A Story First

Picture a car factory with three kinds of workers.

A mechanic works on one specific car: "fix the brakes on this car". They need the car in front of them. That is an ordinary method — it gets self

The solution is hidden so you can try first

6 min read · 10 sections

Run the code

Edit the code and run it here. Each console line with an expected value becomes a test.

PythonInstance, class and static methods; alternative constructors and subclasses