Python：通过循环添加子节点

Question

如何通过循环添加子节点？我正在使用treeView。我已经定义了行数组。在这个Primary1中，Primary2，Primary3是父节点。 Primary1的Secpndary1子节点。 r [1]定义了Primary或​​Secondary并且r [2]定义了父节点名称

rows = [('Primary1', 'Primary', None), ('Primary2', 'Primary', None), 
     ('Secpndary1', 'Secondary', 'Primary1'),('Primary3', 'Primary', None)] 


tree = [] 

for r in rows: 
    tree.append({'node_id': r[1], 'children': []}) 

任何人都可以帮助我吗？

Answer 1

试试这个：

rows = [('Primary1', 'Primary', None), ('Primary2', 'Primary', None), 
    ('Secpndary1', 'Secondary', 'Primary1'),('Primary3', 'Primary', None)] 


tree = [] 

for r in rows: 
    if r[2] is None: 
     tree.append({'node_id': r[0], 'children': []}) 
for r in rows: 
    if r[2] is not None: 
     for node in tree: 
      if node['node_id'] == r[2]: 
       node['children'].append({'node_id': r[0], 'children': []}) 

Answer 2

这是另一种解决方案，它可以工作。

rows = [('Primary1', 'Primary', None), ('Primary2', 'Primary', None), 
     ('Secpndary1', 'Secondary', 'Primary1'),('Primary3', 'Primary', None), ('Secondary2', 'Secondary', 'Primary1')] 

from collections import defaultdict 
dd = defaultdict(list) 
for row in rows: 
    node , _ , child = row 
    x = dd[child].append(node) if child else dd[node] 

print dd 

>>> dd 
defaultdict(<type 'list'>, {'Primary2': [], 'Primary3': [], 'Primary1': ['Secpndary1', 'Secondary2']})