ValueError: Length of values does not match length of index when applying function to dataframe

Question

我有一个自定义函数，我必须将其应用于数据框。但是当我应用该函数时，它会出现上述错误。数据框如下所示：

函数是：

def f(x):
    G = nx.from_pandas_edgelist(x, 'restart_A', 'restart_B')
    l = x.apply(lambda n: ','.join(nx.node_connected_component(G, n['restart_A'])), axis=1)
    return l

df_2['subgroup_name'] = df_2.groupby('Group').apply(f).to_numpy()

我做错了什么？我也做了reset_index，这里看不到

df_2 = pd.DataFrame(
    {
        "Date": ['2020-07-01', '2020-07-01', '2020-07-01'],
        "restart_A": ['User-1013861701','User-1013861701','User-1013861701'],
        "restart_B": ['User-202955957','User-1744844911','User-5711961755'],
        "Group":['G0', 'G0','G0']
    }
)

Answer 1

你能试一试吗？

import pandas as pd
import networkx as nx

df_2 = pd.DataFrame(
    {
        "Date": ['2020-07-01', '2020-07-01', '2020-07-01'],
        "restart_A": ['User-1013861701','User-1013861701','User-1013861701'],
        "restart_B": ['User-202955957','User-1744844911','User-5711961755   '],
        "Group":['G0', 'G0','G0']
    }
)

def f(x):
    G = nx.from_pandas_edgelist(x, 'restart_A', 'restart_B')
    l = x.apply(lambda n: ','.join(nx.node_connected_component(G, n['restart_A'])), axis=1)
    x['subgroup_name'] = l.to_numpy()
    return x

df_2 = df_2.groupby('Group').apply(f)

print(df_2)

输出：

         Date        restart_A           restart_B Group                                      subgroup_name
0  2020-07-01  User-1013861701      User-202955957    G0  User-202955957,User-1013861701,User-5711961755...
1  2020-07-01  User-1013861701     User-1744844911    G0  User-202955957,User-1013861701,User-5711961755...
2  2020-07-01  User-1013861701  User-5711961755       G0  User-202955957,User-1013861701,User-5711961755...

ValueError: Length of values does not match length of index when applying function to dataframe

ValueError: Length of values does not match length of index when applying function to dataframe

python

group-by

networkx

dataframe

pandas