开发手册 欢迎您!
软件开发者资料库

Python大量多个列表(list)合并(合并有相同元素的列表)

本文主要介绍Python中,大量多个列表(list)进行合并,合并具有相同元素的列表 (类以连通分量(图论)问题)。

示例

[[1,2],[3,4,5],[0,4]]      合并后     [[1,2],[0,3,4,5]
[[1],[1,2],[0,2]]             合并后     [[0,1,2]]
[[1, 2], [2, 3], [3, 4]]    合并后     [[1,2,3,4]]

1、使用itertools中combinations合并

from itertools import combinationsdef bfs(graph, start):    visited, queue = set(), [start]    while queue:        vertex = queue.pop(0)        if vertex not in visited:            visited.add(vertex)            queue.extend(graph[vertex] - visited)    return visiteddef connected_components(G):    seen = set()    for v in G:        if v not in seen:            c = set(bfs(G, v))            yield c            seen.update(c)def graph(edge_list):    result = {}    for source, target in edge_list:        result.setdefault(source, set()).add(target)        result.setdefault(target, set()).add(source)    return resultdef concat(l):    edges = []    s = list(map(set, l))    for i, j in combinations(range(len(s)), r=2):        if s[i].intersection(s[j]):            edges.append((i, j))    G = graph(edges)    result = []    unassigned = list(range(len(s)))    for component in connected_components(G):        union = set().union(*(s[i] for i in component))        result.append(sorted(union))        unassigned = [i for i in unassigned if i not in component]    result.extend(map(sorted, (s[i] for i in unassigned)))    return resultprint(concat([[1, 2], [3, 4, 5], [0, 4]]))print(concat([[1], [1, 2], [0, 2]]))print(concat([[1, 2], [2, 3], [3, 4]]))

输出

[[0, 3, 4, 5], [1, 2]]
[[0, 1, 2]]
[[1, 2, 3, 4]]

2、使用networkx合并

import networkx as nxl = [[1,2],[3,4,5],[0,4]]#l = [[1],[1,2],[0,2]]#l = [[1, 2], [2, 3], [3, 4]]G = nx.Graph()#将节点添加到Graph    G.add_nodes_from(sum(l, []))#从节点列表创建边q = [[(s[i],s[i+1]) for i in range(len(s)-1)] for s in l]for i in q:    #向Graph添加边    G.add_edges_from(i)#查找每个组件的图形和列表节点中的所有连接组件[list(i) for i in nx.connected_components(G)]

输出

[[1, 2], [0, 3, 4, 5]]#[[0, 1, 2]]#[[1, 2, 3, 4]]