An adaptation of the eight queens puzzle for any positive integer n > 3.

n_queens.py

from itertools import permutations, dropwhile


def n_queens(n: int) -> list:
    """An adaptation of the eight queens puzzle for any positive integer n > 3.
    :param  - n: a positive integer representing the number of rows, columns, and queens to solve for.
    :return - queen_squares: a list of 2-tuples representing the (0-based) squares to place the queens on, such that no
                             queen is attacked / guarded by another."""
    if n < 4:
        return ["Do it yourself."]

    squares = [(row, col) for row in range(n) for col in range(n)]
    diagonals = {s: {ds for ds in squares if abs(ds[0] - s[0]) == abs(ds[1] - s[1]) and ds != s} for s in squares}

    # Construct a generator for all possible queen placements such that there is only one queen in a given row
    gen = permutations(squares, n)
    no_shared_rows = filter(lambda t: len(set([x for x, _ in t])) == n, gen)

    # Filter down to where there is only one queen per column as well
    no_shared_rows_or_cols = filter(lambda t: len(set([y for _, y in t])) == n, no_shared_rows)

    # Function to look for a placement where no queens share a diagonal
    def shared_diagonals(t):
        for square in t:
            d = diagonals[square]
            if d.intersection(set(t)) == set():
                continue
            else:
                return True
        return False

    # Iterate until a placement is found where no queen shares a diagonal with another
    sol = dropwhile(shared_diagonals, no_shared_rows_or_cols)

    queen_squares = next(sol)

    return queen_squares