My python code,

class Solution:
    def minCostConnectPoints(self, points: List[List[int]]) -> int:
        # Creating Adjacency List
        n = len(points)
        adjList = {i : [] for i in range(n)}
        for i in range(n):
            x1, y1 = points[i]
            for j in range(i + 1, n):
                x2, y2 = points[j]
                distance = abs(x1 - x2) + abs(y1 - y2)
                adjList[i].append([dist, j])
                adjList[j].append([dist, i])
        # Prim's Algorithm
        res = 0
        visited = set()
        minH = [[0, 0]]
        while len(visited) < n:
            x = heapq.heappop(minH)
            distance = x[0]
            i = x[1]
            if i in visited:
                continue
            res += distance
            visited.add(i)
            for neighborDistance, neighbor in adjList[i]:
                if neighbor not in visited:
                    heapq.heappush(minH, [neighborDistance, neighbor])
        return res

produces the following error:

TypeError: unsupported operand type(s) for +=: ‘int’ and ‘builtin_function_or_method’
res += distance

I can’t figure out why distance isn’t treated as an integer