Pairs of multiplied prime number--->N

[deanhystad]

This code was close to working.

def prime_eratosthenes(lim):
    prime_list = []
    for i in range(2, lim+1):
        if i not in prime_list:
            print (i, end = ' ')
            for j in range(i*i, lim+1, i):
                prime_list.append(j)
    return prime_list
  
print(prime_eratosthenes(10))

This prints primes in the correct range, but it does not return these values. Why not? Why are you returning prime_list? This is a list of values that are used to identify primes, not a list of primes. In fact, prime_list is a list of numbers that are not primes as indicated by "if i not in prime_list:" being the test to determine if i is prime.

def prime_eratosthenes(lim):
    primes = []
    not_primes = []
    for i in range(2, lim+1):
        if i not in not_primes:
            primes.append(i)
            for j in range(i*i, lim+1, i):
                not_primes.append(j)
    return primes
  
print(prime_eratosthenes(10))