goldbach.py

from sympy import sieve


def goldbach():
    ''' 
    For each even number > 2,
    it finds a pair of two primes that add up to the number
    '''
    even = 4
    
    while(True):
        printed = False

        if sieve._list[-1] < even:
            sieve.extend(even * 2)

        for a in sieve._list:
            for b in sieve._list:
                if a + b == even:
                    print('{} = {} + {}'.format(even, a, b))
                    even += 2
                    printed = True
                    break
            
            if printed:
                break

        if not printed:        
            print('{} is a counterexample!'.format(even))
            break


if __name__ == '__main__':
    goldbach()