Customize

Do something on the node

New Node From List

You can change the "new_node" method to do something with the node when creating a tree from a list.

In this example, if the node id is "2", a new key will be added to the node.

import json

from typing import Dict

from tree_parsing import Tree


list_tree = [
    {"id": 1, "parent": 0},
    {"id": 2, "parent": 1},
    {"id": 3, "parent": 1},
    {"id": 4, "parent": 2},
    {"id": 5, "parent": 0},
]


class MyTree(Tree):
    def new_node(self, node: Dict) -> None:
        if node['id'] == 2:
            node['new_key'] = 'new value'


tr = MyTree()
tree = tr.tree_from_list(list_tree)
print(json.dumps(tree, indent=4))

Output:

[
    {
        "id": 1,
        "parent": 0,
        "flow": "1",
        "children": [
            {
                "id": 2,
                "parent": 1,
                "new_key": "new value",
                "flow": "1-1",
                "children": [
                    {
                        "id": 4,
                        "parent": 2,
                        "flow": "1-1-1"
                    }
                ]
            },
            {
                "id": 3,
                "parent": 1,
                "flow": "1-2"
            }
        ]
    },
    {
        "id": 5,
        "parent": 0,
        "flow": "2"
    }
]

New Node From Tree

You can change the "new_node_list" method to do something with the node when creating a list from a tree.

In this example, if the node id is "3", a new key will be added to the node.

import json

from tree_parsing import Tree


my_tree = [
    {
        "id": 1,
        "parent": 0,
        "children": [
            {
                "id": 2,
                "parent": 1
            },
            {
                "id": 3,
                "parent": 1
            }
        ]
    },
    {
        "id": 4,
        "parent": 0
    }
]

class MyTree(Tree):
    def new_node_list(self, node: Dict) -> None:
        if node['id'] == 3:
            node['new_key'] = 'new value'

tr = MyTree()
list_tree = tr.list_from_tree(my_tree)
print(json.dumps(list_tree, indent=1))

Output:

[
 {
  "id": 1,
  "parent": 0
 },
 {
  "id": 2,
  "parent": 1
 },
 {
  "id": 3,
  "parent": 1,
  "new_key": "new value"
 },
 {
  "id": 4,
  "parent": 0
 }
]

Changing the flow key

To change the logic of the sequence you can change the methods "make_parent_flow" and "make_child_flow".

Let's see the original implementation:

class MixinTree:
    def __init__(self) -> None:
        self._flow_key: str

    def make_parent_flow(self, node: Dict, parent_number: int) -> None:
        node[self._flow_key] = f"{parent_number + 1}"

    def make_child_flow(
        self, node: Dict, child_number: int, parent_number: int
    ) -> None:
        flow = f"{parent_number}-{child_number + 1}"
        node[self._flow_key] = flow

Now you can change it according to your need.

In this example, the parent node will start with the value "0" and we change the string format by replacing the character "-" with "_"

import json

from typing import Dict

from tree_parsing import Tree


list_tree = [
    {"id": 1, "parent": 0},
    {"id": 2, "parent": 1},
    {"id": 3, "parent": 1},
    {"id": 4, "parent": 2},
    {"id": 5, "parent": 0},
]


class MyTree(Tree):
    def make_parent_flow(self, node: Dict, parent_number: int) -> None:
        node[self._flow_key] = f"{parent_number}"

    def make_child_flow(
        self, node: Dict, child_number: int, parent_number: int
    ) -> None:
        flow = f"{parent_number}_{child_number}"
        node[self._flow_key] = flow


tr = MyTree()
tree = tr.tree_from_list(list_tree)
print(json.dumps(tree, indent=4))

Output:

[
    {
        "id": 1,
        "parent": 0,
        "flow": "0",
        "children": [
            {
                "id": 2,
                "parent": 1,
                "flow": "0_0",
                "children": [
                    {
                        "id": 4,
                        "parent": 2,
                        "flow": "0_0_0"
                    }
                ]
            },
            {
                "id": 3,
                "parent": 1,
                "flow": "0_1"
            }
        ]
    },
    {
        "id": 5,
        "parent": 0,
        "flow": "1"
    }
]