Number of Provinces LeetCode solution in Python

1
class Solution:
2
    def findCircleNum(self, isConnected: List[List[int]]) -> int:
3
        graph = defaultdict(list)
4
        for i, x in enumerate(isConnected):
5
            for j, n in enumerate(x):
6
                if j != i and n == 1:
7
                    graph[i].append(j)
8

9
        visit = set()
10

11
        def dfs(node):
12
            if node not in graph:
13
                return
14
            for neighbor in graph[node]:
15
                if neighbor not in visit:
16
                    visit.add(neighbor)
17
                    dfs(neighbor)
18

19
        count = 0
20
        for i in range(len(isConnected)):
21
            if i in visit:
22
                continue
23
            count += 1
24
            dfs(i)
25
        return count