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Sieve of Eratosthenes

Intermediate · Write the code · from 50 Python Practice Problems with Instant Answer Checking (Beginner to Advanced)

From the lesson: 50 Python Practice Problems with Instant Answer Checking (Beginner to Advanced)

Fifty problems, each with a code editor and real tests. Write your solution, press Check, and see exactly which cases pass. Stuck? Hints reveal one at a time, and the solution unlocks once you have checked at least once. Your code and progress are saved in this browser.

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Write primes_up_to(n) that returns all primes up to and including n using the Sieve of Eratosthenes: start with everything marked prime, then cross out the multiples of each prime.

def primes_up_to(n):
pass
Solution unlocks after your first Check

What Check runs

Your code runs first, then each of these lines. The output must match exactly.

RunsExpected output
primes_up_to(30)[2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
primes_up_to(1)[]

More practice problems

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