Treevizer

Visualize node data structures using Graphviz.

How it works

Treevizer iterates over your datastructure to generate a DOT file and runs Graphviz turn it into an image. The datastructure needs to be built using Nodes.

It also support recursive functions.

Examples

Linked list

Balanced binary tree

Trie

Recursive Fibonacci

Prerequisites

You need to install Graphviz and make sure it is in $PATH.

Cygwin

Graphviz and Pillow need special installation on Cygwin.

Graphviz

Don't install Graphviz in Cygwin, do a windows installation. Otherwise there will be a problem with paths.

Pillow

Pillow is optional, it is only used to create GIFs. If you don't want to create GIFs you don't need to install it.

Don't install Pillow with pip, instead do it with a Cygwin package. Install the Cygwin package python3X-imaging, replace X with your Python version.

Installing

pip install treevizer

Usage

The following structures are supported:

Linked list (ll)

Structure type is called "ll". The config key is called "LinkedList".

Require a Node class with the attributes that fulfill the following class diagram.

Balanced binary tree (bbt)

Structure type is called "bbt". The config key is called "BalancedBinaryTree".

Require a Node class with the attributes that fulfill the following class diagram.

Trie (trie)

Structure type is called "trie". The config key is called "Trie".

Require a Node class with the attributes that fulfill the following class diagram.

The stop attribute marks if node marks a word (True) or not (False).

Recursion

Decorate your recursive function with recursion_viz. It is possible to decorate multiple functions. Each function is identified by the name of your function when creating the PNG or GIF.

Example

import treevizer

@treevizer.recursion_viz
def a_rec_func():
    a_rec_func()


@treevizer.recursion_viz
def another_rec_func():
    another_rec_func()

a_rec_func()
another_rec_func()

treevizer.recursion_to_png("a_rec_func", dot_path="recursion.dot", png_path="recursion.png")
treevizer.recursion_to_png("another_rec_func", dot_path="rec2.dot", png_path="rec2.png")

To configure the dot language, use "Recursion" as key in the json.

Functions

Structure to DOT file

import treevizer

treevizer.to_dot(root, structure_type="bbt", dot_path="tree.dot")
    """
    Generate DOT file from node structure.

    Parameters
    ----------
    root : Node
        Root node for datastructure
    structure_type : str
        Name of the type of datastructure (default is "bbt")
    dot_path : str
        Path to generated DOT file (default is tree.dot)
    """

Structure to PNG

This also creates a DOT file.

import treevizer

treevizer.to_png(root, structure_type="bbt", dot_path="tree.dot", png_path="tree.png")
    """
    Generate DOT file from node structure and use Graphviz to create image.

    Parameters
    ----------
    root : Node
        Root node for datastructure
    structure_type : str
        Name of the type of datastructure (default is "bbt")
    dot_path : str
        Path to generated DOT file (default is tree.dot)
    png_path : str
        Path to generated png file (default is tree.png)
    """

Recursion to PNG

This also creates a DOT file.

import treevizer

@treevizer.recursion_viz
def a_recusive_function():
    a_recusive_function()


treevizer.recursion_to_png(function_name, dot_path="recursion.dot", png_path="recursion.png")
    """
    Generate DOT file of recursive function calls and use Graphviz to create image.

    Parameters
    ----------
    function_name : str
        Name of your decorated function.
    dot_path : str
        Path to generated DOT file (default is recursion.dot)
    png_path : str
        Path to generated png file (default is recursion.png)
    """

Recursion to GIF

import treevizer

@treevizer.recursion_viz
def a_recusive_function():
    a_recusive_function()


treevizer.recursion_to_gif(function_name, gif_path="recursion.dot", duration=800, loop=0)
    """
    Generate PNG files of recursive function calls and use Pillow to create GIF.

    Parameters
    ----------
    function_name : str
        Name of your decorated function.
    gif_path : str
        Path to generated GIF file (default is recursion.gif)
    duration : int
        duration, in miliseconds, of how long each image will be displayed in the GIF (default is 800)
    loop : int
        how many times the GIF should loop after initial loop. 0 to loop infinitely (default is 0)
    """

DOT file to PNG

import treevizer

treevizer.dot_to_png(dot_path="tree.dot", png_path="tree.png")
    """
    Use Graphviz to create image from a DOT file.

    Parameters
    ----------
    dot_path : str
        Path to your DOT file (default is tree.dot)
    png_path : str
        Path to generated png file (default is tree.png)
    """

Configure

Create .dot.json in root folder to change DOT configuration. Available options can be found in Graphviz documentation.

For example to change color of Nodes in image for balanced binary tree use the following.

# .dot.json
{
    "BalancedBinaryTree": {
        "node": {
            "fillcolor": "green"
        }
    }
}

To change size and shape of nodes and color of edges in Linked list use the following.

# .dot.json
{
    "LinkedList": {
        "node": {
            "shape": "square",
            "width": 1.5
        },
        "edge": {
            "color": "red"
        }
    }
}

To change color of the font on edge labels for recursion.

{
    "Recursion": {
        "edge": {
            "fontcolor": "black"
        }
    }
}

Known Errors/Warnings

Known Errors and Warnings

Links

• Pypi
• Source code

License

This project is licensed under the MIT License - see the LICENSE.md file for details