Prime numbers Search

Explanations about prime numbers,:
- Definition of a prime number
- Method to check the primality of a number
- List of prime numbers,
are on this page: Primality test

Programming

Python

This program lists the prime number within a given interval [a, b]. More precisely, it returns the number of prime numbers between a and b.

- As an intermediate step, we use the python prime number test.

- We go through the interval [a, b] with a for loop (index i). If i is prime, it is added to the list (mylist) with the append method.

- n% i means the remainder of the Euclidean division of n by i. If n% i = 0 then i divides n.

def is_prime (number):

 	#1 is not prime
 	if (number == 1):
 		return False

 	for i in range (2, number):
 		if number% i == 0:
 			return False
 	return True 

def prime_numbers(a, b):
	mylist = []
 	for i in range (a, b+1):
 		if is_prime (i):
 			mylist.append(i)
 	return len(mylist), mylist