python prime numbers under x code example

Example 1: python calculate prime numbers until numer

until = 20
[n for n in range(2, until) if all(n % m != 0 for m in range(2, n-1))]

Example 2: list of prime numbers in python

n = 20
primes = []

for i in range(2, n + 1):
	for j in range(2, int(i ** 0.5) + 1):
 		if i%j == 0:
 			break
	else:
		primes.append(i)

print(primes)