# Define memoize(fn) that returns a wrapper using a dict cache keyed by the args tuple

Canonical URL: <https://datadriven.io/problems/define-memoizefn-that-returns-a-wrapper-using-a-dict-cache-2c3d6714>

Domain: Python · Difficulty: medium

## Problem

Define memoize(fn) that returns a wrapper using a dict cache keyed by the args tuple. Decorate a function slow_square(n) that returns n * n. Print slow_square(4), then slow_square(4) again (the second call hits the cache). Expected output is 16 on both lines.

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