Graph Methods in Python (GiMPy) is a Python graph library containing pure Python implementations of a variety of graph algorithms. The goal is clarity in implementation rather than eficiency. Most methods have an accompanying visualization and are thus appropriate for use in the classroom.

Documentation for the API is here:

https://coin-or.github.io/GiMPy

Pypi download page is here:

https://pypi.python.org/pypi/coinor.gimpy

To install, do

pip install coinor.gimpy

##Installation Notes

In order for GiMPy to visualize the graphs it produces, it's necessary to install GraphViz (Important: after installing graphviz, you must add the graphviz bin directory, usually C:\Program Files (x86)\Graphviz2.38\bin, to your PATH) and choose one of these additional methods for display:

• Recommended: xdot along with PyGtk and call set_display_mode('xdot')
• Python Imaging Library and call set_display_mode('PIL')
• Pygame and call set_display_mode('pygame')
• Call set_display_mode('file') to just write files to disk that have to then be opened manually.

It is also possible to typeset labels in LaTex and to output the graph in LaTex format using dot2tex. After installing dot2tex, this can be done by simply calling the method write(basename='fileName', format='dot'), and then doing dot2tex --tmath fileName.dot or by calling set_display_mode('dot2tex') and then display() as usual. At the moment, the latter only seems to work with version 2.9.0dev available here. For the former method, just using easy_install dot2tex should work fine.

On Windows, if you want to use xdot, there are some additional particulars.

• You must install the 32-bit version of Python 2.7
• You must install the PyGtk version 2.22.6. Version 2.24 is buggy on Windows.
• You must install version 0.6 of xdot with e.g., pip install xdot==0.6

There have been reports of incompatibilities with recent versions of PyGtk, but I have not attempted yet to track this down. If things break, you may try some variant of the instructions above for installing on Windows.

##Examples

###Forestry Model ###Display Window in XDot ###Lehigh ISE Prerequisite Graph ###Graph of Actors Starring Together in Movies in IMDB ###Branch and Bound Tree ###SAT Game Tree ###Flow Problem