List of primes under a million This is my first code golf question, and a very simple one at that, so I apologise in advance if I may have broken any community guidelines.

The task is to print out, in ascending order, all of the prime numbers less than a million. The output format should be one number per line of output.

The aim, as with most code golf submissions, is to minimise code size. Optimising for runtime is also a bonus, but is a secondary objective.
Python 3, 45 bytes

k=P=1
while k&lt;1e6:P%k&gt;0==print(k);P*=k*k;k+=1

Try it online!
By the time the loop reaches testing k, it has iteratively computed the squared-factorial P=(k-1)!^2. If k is prime, then it doesn't appear in the product 1 * 2 * ... * (k-1), so it's not a factor of P. But, if it's composite, all its prime factors are smaller and so in the product. The squaring is only actually needed to stop k=4 from falsely being called prime.
More strongly, it follows from Wilson's Theorem that when k is prime, P%k equals 1. Though we only need that it's nonzero here, it's useful in general that P%k is an indicator variable for whether k is prime.
Thanks to @Sisyphus for 1 byte with P%k&gt;0==print(k) using chained operator short-circuiting in place of P%k and print(k).