Accounts Merge

class Solution:
    def accountsMerge(self, accounts: List[List[str]]) -> List[List[str]]:
        name = {}
        n = len(accounts)
        rep ={i : i for i in range(n)}

        def find(node):
            if rep[node] != node:
                rep[node] = find(rep[node])
            return rep[node]
        
        def union(x, y):
            
            xrep = find(x)
            yrep = find(y)
            
            if xrep!=yrep:
                rep[yrep] = xrep
        
        for idx in range(n):
            for account in accounts[idx][1:]:
                if account in rep:
                    union(rep[account],idx)
                rep[account] = idx

        ans = defaultdict(list)
        for key in rep:
            parent = find(key)
            if isinstance(key,str):
                ans[parent].append(key)
        # print(ans)
        answer = []
        for key in ans:
            answer.append([accounts[key][0]] + sorted(ans[key]))
        return answer