prime functions

primes.py

def is_prime_number(x):
        ''' Function to know if x is a prime number.
        '''
        for i in range(floor(sqrt(x))):
            if x % i == 0:
                return False
        return True
        
def sieve_of_eratosthenes(start, end):
        ''' Brute force method to compute primes.
        '''
        t = dict(zip(range(start, end), [True] * (end-start)))
        for i in range(start, floor(sqrt(end))):
            if t[i] == True:
                j = i**2
                while j < end:
                    t[j] = False
                    j += i
        return t