Closures

Main idea

Inner function remembers outer scope variables.

Tip

Use to create configured function factories.

Watch out

Captured variable surprises in loops.

Read this next

This lesson is about Closures. You are in the Functional Programming part of the course.

Main idea:
Inner function remembers outer scope variables.

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

Tip:
Use to create configured function factories.

Common mistake:
Captured variable surprises in loops.

Your challenge:
Build multiplier factory closure.

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 Closures.

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

if __name__ == "__main__":
    main()

Challenge

Build multiplier factory closure.

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 Closures
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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