Note : I changed it from printing out just the numbers to appending the numbers to an array and then printing out the array. Now if you input a prime number it returns : Īnd any other number such as 20 : If is_prime(a)=True: #if the inputted number is prime it automatically appends that number to the list and breaks since prime numbers don't have any other factorsĭef remove_duplicates(values): #here it checks for duplicates #print(n) #otherwise it prints out the number since it is a prime number #print(n) #if one of the factors is 2 it prints it because it is a prime number

When you input a prime number it returns a blank array. But if no other factors exist for that number, then that number is prime.

This is because 1 times any number will always be that same number. If we run this and I input 10 it returns this : Every number has factors of 1 and itself. Print(n) #otherwise it prints out the number since it is a prime numberįor n in b: #iterates through the list of factors and checks if they are prime If n % 2 = 0 or n <= 1: # if it is less than one or is a factor of 2 it returns false and does nothingįor divisor in range(3, sqr, 2): #checks for other divisors Print(n) #if one of the factors is 2 it prints it because it is a prime number Instead of printing it you could also append it to another list by replace the print(n) with something else. When using the Sieve of Eratosthenes method, the important thing to note is that you only have to remove numbers that are products of. Here you can print the list of factors and then iterate through the list of factors and this program will print out the ones that are prime. The first code block you posted is the easiest example for me to explain this: primes range (2, 20) for i in range (2, 8): primes filter (lambda x: x i or x i, primes) print primes.

Prime number list to 100 python