QGraphViz

A PyQT based GraphViz builder/renderer (100% opensource)

Introduction

I was searching for a handy tool to code graphs using python then visualize them within my software. I found about graphviz which is a great tool to build graphs.

The problem is that you need to install the graphviz software in order to compile your file and render it.

There is a graphviz package on PYPI that allows creating dot code that can then be processed by graphviz, but in practice, you need to install graphviz and somehow add it to your path in order to execute the render command.

PyGraphviz is another package that can be used. But as you can read in their documentation, you still need to install Graphviz.

I also found this visualizer based on pyQt4. It is a simple Qt based visualizer that tracks the updates on the .gv file and redraws it in realtime: DDorch/GraphVizLiveUpdateViewer

So since I didn't find any package out there that satifies my needs, I decided to create a pyQT5 based Graphviz tool that can visualize Graphviz code without the need to install Graphviz and provide it with MIT licence, so that other people can simply use it in their software.

Objective

Build python pyQT5 based QWidget that can visualize graphs and allow realtime interaction with graphs add edges and nodes, change attributes ...

Requirements

As its name suggests, this module needs you to install pyqt5 package first.

pip install pyqt5

Installation

pip install QGraphViz

Actual status

1. Simple graphs visualization (nodes + edges)
2. Simple gv files read/write
3. Graph nodes can hold custom parameters that can be used by the application
4. Graph nodes are now manipulable and we can add nodes and link them using the QWidget gui, wa can also delete nodes.
5. The application can accept or refuse edges creation and even add custom parameters to the edges
6. The nodes can be double clicked and an event is sent to the application allowing it to do custom
7. User application is informed wen a new connection is created between two nodes, when a node is selected or when it is double clicked.
8. User application is informed when a edge is selected or double clicked.
9. Only two supported node shapes (box or oval)
10. Advanced nodes shapes are not yet implemented
11. Only the dot layout is implemented
12. Supported shapes are box, circle, triangle, diamond, polygon
13. Supported custom node shapes using png images

Example code

You can find an example code for manipulating graphs in examples/QGraphViewer.py.

Change log

To view different changes from release to the other please view our changelog.

Warning

If you are aiming to export a .gv file of your graph, don't use images as shapes because this is not supported by real graphviz tool. You can use it safely if you save your graph in our json format.

Special thanks

Here I'll be citing the contributions of others than myself and show them gratitude for help :

• Many thanks to Ederrod for adding icon shaped nodes.
• Many thanks to gregori0o for fixing few bugs.
• Many thanks to ZeJackOfSpades for adding directed graphs option.

If any one has ideas to enhance this tool, you are welcome to contribute.