treelib

library1.8.0pypypi✓ verified 24d ago

TreeLib provides a Python implementation for creating, manipulating, and visualizing tree data structures. It allows users to build hierarchical data, traverse nodes, and render trees to various outputs like console text or Graphviz. It is actively maintained with a moderate release cadence, with the current version being 1.8.0.

data

pip install treelib

github ↗package ↗

INSTALL

IMPORT

SIG · TREELIB

treelib

datapythonv1.8.0

Install

1.6s avg

Import

39ms

Disk

16MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.8.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.042s · 18.1MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 1.6s · import 0.035s · 19MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Tree

✓ from treelib import Tree

This example demonstrates creating a new tree, adding several nodes with unique identifiers and parent-child relationships, and then printing the tree to the console.

from treelib import Tree tree = Tree() tree.create_node("Harry", "harry") # Root node tree.create_node("Jane", "jane", parent="harry") tree.create_node("Bill", "bill", parent="harry") tree.create_node("Diane", "diane", parent="jane") tree.create_node("George", "george", parent="jane") tree.create_node("Mark", "mark", parent="bill") tree.show()

Debug

Known issues

breakingtreelib v1.8.0 and later no longer support Python 3.6 due to its End-of-Life. Attempting to install or run treelib 1.8.0+ on Python 3.6 will result in errors.

fix

Upgrade your Python interpreter to 3.7 or higher. If you must use Python 3.6, you will need to pin treelib to a version prior to 1.8.0 (e.g., `treelib<1.8`).

affects: >=1.8.0

breakingThe `treelib.plugin` module, including `BaseConnector` and `NodeMixin`, was removed in v1.7.0. Code relying on these deprecated components will break.

fix

Refactor code to avoid the `plugin` module. For custom node behavior or mixins, use standard Python inheritance or create your own mixin classes directly without depending on `treelib.plugin.NodeMixin`.

affects: >=1.7.0

gotchaMethods like `Tree.to_graphviz()` require the `graphviz` Python package (and the Graphviz system library) to be installed separately. Without these, such methods will raise an `ImportError` or similar error.

fix

Install the `graphviz` Python package with `pip install treelib[graphviz]` or `pip install graphviz`. Additionally, ensure the Graphviz system utility is installed on your operating system and discoverable in your PATH.

affects: all

gotchaEach node in a `treelib.Tree` must have a unique `identifier`. Reusing identifiers for different nodes will lead to unexpected behavior, as `treelib` uses them internally for lookup and maintaining structure. This is often confused with the `tag` attribute, which can be duplicated.

fix

Always provide a unique `identifier` when calling methods like `tree.create_node()`. If you need multiple nodes to share the same display text, use different identifiers for each node while keeping their `tag` attribute the same.

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'treelib'

The treelib package is not installed in the current Python environment.

fix

Install the library using pip: `pip install treelib`

KeyError: 'parent_tag: some_tag' not found in the tree

The parent_tag specified for Tree.add_node() does not correspond to an existing node's identifier in the tree, or parent_tag is None for a node that is not the root.

fix

Ensure the parent_tag refers to an existing node's identifier, or set it to None only when adding the very first (root) node.

AttributeError: 'NoneType' object has no attribute 'tag'

A Node object was not found using tree.get_node(), which returned None, and subsequent code attempted to access an attribute (like 'tag') on this None object.

fix

Always check if the result of `tree.get_node()` is not `None` before attempting to access its attributes, or handle the case where the node might not exist.

FileNotFoundError: [Errno 2] No such file or directory: 'dot'

The Graphviz command-line tools, specifically the 'dot' executable, are not installed or not accessible in the system's PATH, which treelib requires for the export_dot() method.

fix

Install the Graphviz command-line tools for your operating system (e.g., `sudo apt-get install graphviz` on Debian/Ubuntu, `brew install graphviz` on macOS) and ensure its executable is in your system's PATH.

treelib.tree.NodeIDAbsentError: Parent identifier 'some_non_existent_id' not found.

When calling `tree.add_node()`, the provided `parent` identifier does not correspond to an existing node in the tree.

fix

Ensure that the parent node exists in the tree *before* attempting to add a child node to it, or specify `parent=None` for the root node.

Upgrade

Version history

1.8.0latest on PyPI · released Jun 29, 2025

Audit

Dependencies

graphvizoptionalRequired for `Tree.to_graphviz()` and other visualization methods. The Graphviz system utility must also be installed.

Agent activity

24 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/caesar0301/treelib ↗

packagehttps://pypi.org/project/treelib/ ↗