GCol: A High-Performance Python Library for Graph Colouring

Graph colouring is the computational problem of assigning colours to entities of a graph so that adjacent entities receive different colours.The aim is to use as few colours as possible.In general terms, a graph is a mathematical object comprising a set of nodes and a set of edges that join pairs of nodes.Graphs are also known as networks, nodes as vertices, and edges as links.Examples of graph colouring are shown in Figure 1, which help to demonstrate the following principles.