n-queen algorithm animated in the terminal

n_queen.py

from time import sleep
from os import system

"""
After spending the day trying to understand this algorithm, i decided to animated it in terminal.
Makes a lot more sense, so sharing.
"""

delay = .05

def n_queens(n):
    def solve_n_queens(row, col_placement):
        if row == n:
            print("HURRAH!")
            sleep(1)
            result.append(col_placement.copy())
            return
        for col in range(n):
            # Test if a newly placed queen will conflict
            # any earlier queens placed before.
            conflict = False
            cols_to_backtest = col_placement[:row]
            to_test = col_placement[:]
            to_test[row] = col
            for i, c in enumerate(cols_to_backtest):
                if abs(c - col) in (0, row - i):
                    conflict = True
                    break
            print('\n'*5)
            system('clear')
            if not conflict:
                col_placement[row] = col
                draw_board(col_placement)
                sleep(delay)
                solve_n_queens(row + 1, col_placement[:])
            else:
                draw_board(to_test, row, col, conflict)
                sleep(delay)

    result = []
    solve_n_queens(0, [-1] * n)
    return result

def comp(a, b):
    return sorted(a) == sorted(b)


def draw_board(queens, row=-1, col=-1, conflict=False):
    n = len(queens)
    for i in range(n):
        print('   |', end='')
        for j in range(n):
            print('---|', end='')
        print('')
        if queens[i] != -1:
            print(f' {queens[i]} |', end='')
        else:
            print(f'   |', end='')
        for j in range(n):
            if queens[i] == j:
                c = 'o'
                if i == row and j == col:
                    c = '.'
                    if conflict:
                        c = 'x'
            else:
               c = ' '
            print(' {} |'.format(c), end='')
        print('')

system('clear')

for queens in n_queens(6):
    draw_board(queens)
    print('   '+'-'*17)
    pass