next_prime.py

next_prime.py

#!/usr/bin/env python

import math

def isPrime(n):
    """ Check if n is prime using trial division as our primality test """

    if n%2 == 0 and n > 2:
        # takes care of all the even numbers
        return False

    for i in range(3, int(math.sqrt(n))+1, 2):
        if(n%i == 0):
            # Found a number which divides n therefore n is not prime
            return False
    return True

def main():
    lowerbound = int(raw_input('lowerbound : '))
    num_primes = int(raw_input('number of primes to find: '))

    # Added count and current variable in case you need to
    # keep user input for later on. Such as to print it out at the end
    # If you didn't need it you could also use num_primes as the
    # while loop counter and lowerbound as your current
    count = 0 # count represents the number of primes found
    current = lowerbound # represents the current number to check for

    while count < num_primes:
        if isPrime(current):
            # Found a prime!
            print current
            count += 1
        current += 1

if __name__ == "__main__":
    main()