row = [' ', ' ', ' ']
matrix = [row, row, row]  # the problem is 3 of same row
print(matrix)
matrix[0][0] = 'X'
print(matrix)

print()

matrix = [[' ', ' ', ' '], [' ', ' ', ' '], [' ', ' ', ' ']]  # 3 different rows
print(matrix)
matrix[0][0] = 'X'
print(matrix)