AttributeError: missing self

What this problem practises

Object-oriented bugs hide in state: class attributes shared by every instance, mutable defaults declared in __init__ signatures, and methods that mutate self when the caller expected a copy.

This is a fix-the-bug problem: a short program is given in its broken state, and the task is to repair the code so it produces the required output. The interactive editor runs your fixed version in the browser and checks it for you — no setup, no local interpreter.

Difficulty: medium — expect to hold two interacting rules in your head at once, such as a boundary combined with a mutation.

The challenge

This program crashes with AttributeError when calling show(). Fix __init__ so it prints Kiran.

The code runs in PyDebug’s in-browser compiler. Open the problem, run the snippet, watch the exact error or output, and keep iterating until it is right. Signed-in solves count toward XP and your daily streak.

The snippet

The interactive editor pre-fills exactly this code, broken and ready to repair:

class Student:
    def __init__(self, name):
        name = name
    def show(self):
        print(self.name)
s = Student('Kiran')
s.show()

More oop problems

• AttributeError: missing self medium
• AttributeError: missing self medium
• TypeError: method called on the class medium

Keep going

• Python debugging guide — a systematic method for finding bugs like this one fast.
• Browse every oop problem in this topic.
• Common Python errors and what they actually mean, plus the Python glossary for any term used on this page.