寻找终极 parent

Question

我正在努力寻找最终的 parent 与 Dir pandas。但这项任务有一个特点，图表并不真正适合，或者我根本不知道如何正确使用它。输入：

Child	Parent	Class
1001	8888	A
1001	1002	D
1001	1002	C
1001	1003	C
1003	6666	G
1002	9999	H

输出：

Child	Ultimate_Parent	Class	Connection
1001	8888	A	Direct
1001	9999	D	Indirect
1001	9999	C	Indirect
1001	6666	C	Indirect
1003	6666	G	Direct
1002	9999	H	Direct

我愿意：

import pandas as pd 
import networx as nx 
df = pd.DataFrame({'Child': ['1001', '1001', '1001', '1001', '1003', '1004'], 'Parent': ['8888', '1002', '1002', '1003', '6666', '9999'],'Class': ['A','D','C','C','G','H']})
    def get_hierarchy (df):
        DiG=nx.from_pandas_adgelist (df,'child','parent',create_using=nx.DiGraph())
        return pd.DataFrame.from_records([(n1,n2) for n1 in DiG.nodes() for n2 in nx.ancestors(DiG, n1)], columns=['child','Ultimate_parent'])
    df=df.toPandas()
    df=get_hierarchy(df)
    return df

我不知道如何在这里使用 Class 属性，用 D 和 C 类.

显示两次 1001

Answer 1

使用G.predecessors检测当前Parent是否是树的根。如果是，则连接为 Direct 否则连接为 Indirect.

G = nx.from_pandas_edgelist(df, source='Parent', target='Child',
                            create_using=nx.DiGraph)

roots = [node for node, degree in G.in_degree() if degree == 0]

ultimate_parent = [node if node in roots else list(G.predecessors(node))[0] 
                       for node in df['Parent']]

df['Ultimate_Parent'] = ultimate_parent
df['Connection'] = np.where(df['Parent'] == df['Ultimate_Parent'],
                            'Direct', 'Indirect')

输出：

>>> df
   Child  Parent Class  Ultimate_Parent Connection
0   1001    8888     A             8888     Direct
1   1001    1002     D             9999   Indirect
2   1001    1002     C             9999   Indirect
3   1001    1003     C             6666   Indirect
4   1003    6666     G             6666     Direct
5   1002    9999     H             9999     Direct

寻找终极 parent

Finding ultimate parent

python

hierarchy

pandas

pyspark