Class vs Instance Attributes

Main idea

Class attrs shared by all instances; instance attrs unique.

Tip

Shared constants belong to class.

Watch out

Mutating shared class list unexpectedly.

Read this next

This lesson is about Class vs Instance Attributes. You are in the Object-Oriented Programming part of the course.

Main idea:
Class attrs shared by all instances; instance attrs unique.

How to learn it: type a very small program first. Run it. Change one line and run again.

Tip:
Shared constants belong to class.

Common mistake:
Mutating shared class list unexpectedly.

Your challenge:
Track total users created via class variable.

Scroll down to the challenge lab. Run your code there. When the output meets the task and the checks pass, press the green button to finish this topic.

Example code

Copy this example if it helps. Change it so it matches Class vs Instance Attributes.

# Topic: Class vs Instance Attributes
def main():
    sample = "edit me"
    # TODO: apply Class vs Instance Attributes concept here
    result = sample
    print("Result:", result)

if __name__ == "__main__":
    main()

Challenge

Track total users created via class variable.

Before you can finish: your output should include at least 16 characters; at least 1 non-empty line(s); no crash traceback—fix errors until the program runs cleanly.

Use Run. Read the output. Change your code until the task is done.

Starter reference

# Challenge starter for Class vs Instance Attributes
def solve():
    # Write your solution here
    pass

print("Update solve() and run")

Your code

The first Run may load Python in your browser (one-time). Later runs are faster.

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