CODEWITHSUNDEEP
pythonfunctionruntime-error
Moe
Moe

Reputation: 115

Python TypeError takes 2 positional arguments but 3 are given

This code is supposed to calculate the shortest Manhattan distance between a node state (character position) and the nearest food location.

state = ((x, y), ("some status"))

food_coords = [(x, y), (x, y), (x, y)]

note: (x,y) are some coordinates in a grid

But, when the get_manhattan_distance(pos, food_pos) executes, I get the following error: TypeError: GridProblem.get_manhattan_distance() takes 2 positional arguments but 3 were given

note: when this function is called, the character (state position) and the food position are on the same grid location.

# helper function to calculate the manhattan distance
def get_manhattan_distance(p, q):
    distance = 0
    for p_i,q_i in zip(p,q):
        distance += abs(p_i - q_i)
    return distance

# heuristic = Manhattan distance
def h(self, node):
    if self.is_goal(node.state):
        return 0
    pos = node.state[0] #current position (x, y)
    x_coord = node.state[0][0]
    y_coord = node.state[0][1]
    distances = []
    for food_pos in self.food_coords:
        print('pos=',pos)
        print('food_pos=',pos)
        distances.append(self.get_manhattan_distance(pos, food_pos))
    distances.sort()
    return distances[0]

Upvotes: 2

Views: 15224

Answers (1)

George Wilhelm Hegel
George Wilhelm Hegel

Reputation: 153

Every method of a class, receives its object as input. That is what "self" parameter in the method definition refers to. Just add self parameter to your get_manhattan_distance method definition and the problem will be gone. like this:

get_manhattan_distance(self, p, q):

Upvotes: 4

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