I'm Programming a Roguelike in Python and I need a Specific Monster Following Script

I'm Programming a Roguelike in Python and I need a Specific Monster
Following Script

I'm using libtcod and python to make a roguelike; the tutorial I'm
following the monsters only follow you if you're in their field of view.
Obviously this is insufficient; as it means you can turn a corner and they
don't follow you around the corner.
I tried something like this;
class BasicMonster:
def take_turn(self, seen):
self.seen = False
monster = self.owner
if lib.map_is_in_fov(fov_map, monster.x, monster.y):
self.seen == True
if self.seen == True:
self.move_towards(player.x, player.y)
To no avail. It returns that "TypeError: take_turn() takes exactly 2
arguments (1 given)". Not sure how to implement this.