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TreeValue is a generalized tree-based data structure mainly developed by OpenDILab Contributors.

Almost all the operations can be supported in the form of trees in a convenient way to simplify the structure processing when the calculation is tree-based.

Outline

• Overview
• Getting Started
  • Prerequisite
  • Installation
  • Quick Usage
  • Tutorials
  • External
• Speed Performance
• Change Log
• Feedback and Contribute
• Citation
• License

Overview

When we build a complex nested structure, we need to model it as a tree structure, and the native list and dict in Python are often used to solve this problem. However, it takes a lot of codes and some complex and non-intuitive calculation logic, which is not easy to modify and extend related code and data, and parallelization is impossible.

Therefore, we need a kind of more proper data container, named TreeValue. It is designed for solving the following problems:

• Ease of Use: When the existing operations are applied to tree structures such as dict, they will become completely unrecognizable, with really low readability and maintainability.
• Diversity of Data: In the tree structure operation, various abnormal conditions (structure mismatch, missing key-value, type mismatch, etc.) occur from time to time, and the code will be more complicated if it needs to be handled properly.
• Scalability and Parallelization: When any multivariate operation is performed, the calculation logic needs to be redesigned under the native Python code implementation, and the processing will be more complicated and confusing, and the code quality is difficult to control.

Getting Started

Prerequisite

treevalue has been fully tested in the Linux, macOS and Windows environments and with multiple Python versions, and it works properly on all these platforms.

However, treevalue currently does not support PyPy, so just pay attention to this when using it.

Installation

You can simply install it with pip command line from the official PyPI site.

pip install treevalue

Or just from the source code on github

pip install git+https://github.com/opendilab/treevalue.git@main

For more information about installation, you can refer to the installation guide.

After this, you can check if the installation is processed properly with the following code

from treevalue import __version__
print('TreeValue version is', __version__)

Quick Usage

You can easily create a tree value object based on FastTreeValue.

from treevalue import FastTreeValue

if __name__ == '__main__':
    t = FastTreeValue({
        'a': 1,
        'b': 2.3,
        'x': {
            'c': 'str',
            'd': [1, 2, None],
            'e': b'bytes',
        }
    })
    print(t)

The result should be

<FastTreeValue 0x7f6c7df00160 keys: ['a', 'b', 'x']>
├── 'a' --> 1
├── 'b' --> 2.3
└── 'x' --> <FastTreeValue 0x7f6c81150860 keys: ['c', 'd', 'e']>
    ├── 'c' --> 'str'
    ├── 'd' --> [1, 2, None]
    └── 'e' --> b'bytes'

And t is structure should be like this

Not only a visible tree structure, but abundant operation supports is provided. You can just put objects (such as torch.Tensor, or any other types) here and just call their methods, like this

import torch

from treevalue import FastTreeValue

t = FastTreeValue({
    'a': torch.rand(2, 5),
    'x': {
        'c': torch.rand(3, 4),
    }
})

print(t)
# <FastTreeValue 0x7f8c069346a0>
# ├── a --> tensor([[0.3606, 0.2583, 0.3843, 0.8611, 0.5130],
# │                 [0.0717, 0.1370, 0.1724, 0.7627, 0.7871]])
# └── x --> <FastTreeValue 0x7f8ba6130f40>
#     └── c --> tensor([[0.2320, 0.6050, 0.6844, 0.3609],
#                       [0.0084, 0.0816, 0.8740, 0.3773],
#                       [0.6523, 0.4417, 0.6413, 0.8965]])

print(t.shape)  # property access
# <FastTreeValue 0x7f8c06934ac0>
# ├── a --> torch.Size([2, 5])
# └── x --> <FastTreeValue 0x7f8c069346d0>
#     └── c --> torch.Size([3, 4])
print(t.sin())  # method call
# <FastTreeValue 0x7f8c06934b80>
# ├── a --> tensor([[0.3528, 0.2555, 0.3749, 0.7586, 0.4908],
# │                 [0.0716, 0.1365, 0.1715, 0.6909, 0.7083]])
# └── x --> <FastTreeValue 0x7f8c06934b20>
#     └── c --> tensor([[0.2300, 0.5688, 0.6322, 0.3531],
#                       [0.0084, 0.0816, 0.7669, 0.3684],
#                       [0.6070, 0.4275, 0.5982, 0.7812]])
print(t.reshape((2, -1)))  # method with arguments
# <FastTreeValue 0x7f8c06934b80>
# ├── a --> tensor([[0.3606, 0.2583, 0.3843, 0.8611, 0.5130],
# │                 [0.0717, 0.1370, 0.1724, 0.7627, 0.7871]])
# └── x --> <FastTreeValue 0x7f8c06934b20>
#     └── c --> tensor([[0.2320, 0.6050, 0.6844, 0.3609, 0.0084, 0.0816],
#                       [0.8740, 0.3773, 0.6523, 0.4417, 0.6413, 0.8965]])
print(t[:, 1:-1])  # index operator
# <FastTreeValue 0x7f8ba5c8eca0>
# ├── a --> tensor([[0.2583, 0.3843, 0.8611],
# │                 [0.1370, 0.1724, 0.7627]])
# └── x --> <FastTreeValue 0x7f8ba5c8ebe0>
#     └── c --> tensor([[0.6050, 0.6844],
#                       [0.0816, 0.8740],
#                       [0.4417, 0.6413]])
print(1 + (t - 0.8) ** 2 * 1.5)  # math operators
# <FastTreeValue 0x7fdfa5836b80>
# ├── a --> tensor([[1.6076, 1.0048, 1.0541, 1.3524, 1.0015],
# │                 [1.0413, 1.8352, 1.2328, 1.7904, 1.0088]])
# └── x --> <FastTreeValue 0x7fdfa5836880>
#     └── c --> tensor([[1.1550, 1.0963, 1.3555, 1.2030],
#                       [1.0575, 1.4045, 1.0041, 1.0638],
#                       [1.0782, 1.0037, 1.5075, 1.0658]])

Tutorials

For more examples, explanations and further usages, take a look at:

• Quick Start
  • Create a Simplest Tree
  • Create a Slightly Complex Tree
• Basic Usage
  • Create a Tree
  • Edit a Tree
  • Do Index or Slice Calculation on The Tree
  • Do Math Calculation on The Tree
  • Make Function Tree-Supported
• Advanced Usage
  • Function Modes
  • Inheriting on Trees
  • Process Missing Values
  • Functional Utilities
  • Structural Utilities
  • Tree Utilities
  • Flatten Utilities
  • IO Utilities
  • Object Oriented Usage
  • Costumize My TreeValue Class
  • Visualization of TreeValue

External

We provide an official treevalue-based-wrapper for numpy and torch called DI-treetensor since the treevalue is often used with libraries like numpy and torch. It will actually be helpful while working with AI fields.

Speed Performance

Here is the speed performance of all the operations in FastTreeValue; the following table is the performance comparison result with dm-tree. (In DM-Tree, the unflatten operation is different from that in TreeValue, see: Comparison Between TreeValue and DM-Tree for more details.)

	flatten	flatten(with path)	mapping	mapping(with path)
treevalue	---	511 ns ± 6.92 ns	3.16 µs ± 42.8 ns	1.58 µs ± 30 ns
	flatten	flatten_with_path	map_structure	map_structure_with_path
dm-tree	830 ns ± 8.53 ns	11.9 µs ± 358 ns	13.3 µs ± 87.2 ns	62.9 µs ± 2.26 µs

The following 2 tables are the performance comparison result with jax pytree.

	mapping	mapping(with path)	flatten	unflatten	flatten_values	flatten_keys
treevalue	2.21 µs ± 32.2 ns	2.16 µs ± 123 ns	515 ns ± 7.53 ns	601 ns ± 5.99 ns	301 ns ± 12.9 ns	451 ns ± 17.3 ns
	tree_map	(Not Implemented)	tree_flatten	tree_unflatten	tree_leaves	tree_structure
jax pytree	4.67 µs ± 184 ns	---	1.29 µs ± 27.2 ns	742 ns ± 5.82 ns	1.29 µs ± 22 ns	1.27 µs ± 16.5 ns

	flatten + all	flatten + reduce	flatten + reduce(with init)	rise(given structure)	rise(automatic structure)
treevalue	425 ns ± 9.33 ns	702 ns ± 5.93 ns	793 ns ± 13.4 ns	9.14 µs ± 129 ns	11.5 µs ± 182 ns
	tree_all	tree_reduce	tree_reduce(with init)	tree_transpose	(Not Implemented)
jax pytree	1.47 µs ± 37 ns	1.88 µs ± 27.2 ns	1.91 µs ± 47.4 ns	10 µs ± 117 ns	---

This is the comparison between dm-tree, jax-libtree and us, with flatten and mapping operations (lower value means less time cost and runs faster)

The following table is the performance comparison result with tianshou Batch.

	get	set	init	deepcopy	stack	cat	split
treevalue	51.6 ns ± 0.609 ns	64.4 ns ± 0.564 ns	750 ns ± 14.2 ns	88.9 µs ± 887 ns	50.2 µs ± 771 ns	40.3 µs ± 1.08 µs	62 µs ± 1.2 µs
tianshou Batch	43.2 ns ± 0.698 ns	396 ns ± 8.99 ns	11.1 µs ± 277 ns	89 µs ± 1.42 µs	119 µs ± 1.1 µs	194 µs ± 1.81 µs	653 µs ± 17.8 µs

And this is the comparison between Tianshou Batch and us, with cat , stack and split operations (lower value means less time cost and runs faster)

Test benchmark code can be found here:

• Comparison with dm-tree
• Comparison with jax-libtree
• Comparison with tianshou Batch

Change Log

Version History [click to expand]

• 2022-05-03 1.3.1: Change definition of getitem, setitem and delitem; add pop method for TreeValue class.
• 2022-03-15 1.3.0: Add getitem, setitem and delitem for adding, editing and removing items in TreeValue class.
• 2022-02-22 1.2.2: Optimize union function; add walk utility method.
• 2022-01-26 1.2.1: Update tree printing; add keys, values, items on TreeValue; add comparision to facebook nest library.
• 2022-01-04 1.2.0: Add flatten_values and flatten_keys; fix problem in mapping function; add support for potc.
• 2021-12-03 1.1.0: Add version information; fix bug of default value; add flatten and unflatten; optimization speed performance.
• 2021-10-24 1.0.0: Greatly optimize the speed performance using cython, overhead has been reduced to a negligible level.

Feedback and Contribute

Welcome to OpenDILab community - treevalue!

If you meet some problem or have some brilliant ideas, you can file an issue.

Scan the QR code and add us on Wechat:

Or just contact us with slack or email (opendilab.contact@gmail.com).

Please check Contributing Guidances.

Thanks to the following contributors!

Citation

@misc{treevalue,
    title={{TreeValue} - Tree-Structure Computing Solution},
    author={TreeValue Contributors},
    publisher = {GitHub},
    howpublished = {\url{https://github.com/opendilab/treevalue}},
    year={2021},
}

License

treevalue released under the Apache 2.0 license. See the LICENSE file for details.