def brute_force(goal=1000):
    """Brute force method to find Pythagorean triplet with some of goal.

    Since a < b < c:

    * a is less than a third (1/3) of the goal, (a < goal//3)
    * b is greater than a and less than half(1/2) of the goal (a < b < goal//2)
    * c is one of the remaining numbers (goal//2 <= c),
      c is goal minus the sum of a and b (goal - (a + b)).

    :param goal: The sum of the pythagorean triplet
    :return: Tuple of Pythagorean triplet whose sum is the goal
    or None if not found
    """
    a_numbers = range(goal//3, 2, -1)
    b_numbers = range(goal//2, 2, -1)

    pythagorean_triplet = [(a, b, c,)
                           for a in a_numbers
                           for b in b_numbers
                           for c in [(goal - (a + b)), ]
                           if a*a + b*b == c*c
                           ]

    return pythagorean_triplet[0] if pythagorean_triplet else None