abstract 0.1.4

Python library for creating and drawing graphs and taking advantage of graph properties

Abstract

Abstract is a Python library for creating and drawing graphs and taking advantage of graph properties.

Installation

pip install abstract

or

pip install git+https://github.com/idin/abstract.git

Graph

In computer science, a graph is an abstract data type that is meant to implement the undirected graph and directed graph concepts from mathematics; specifically, the field of graph theory. [1]

A graph data structure consists of a finite (and possibly mutable) set of vertices or nodes or points, together with a set of unordered pairs of these vertices for an undirected graph or a set of ordered pairs for a directed graph. These pairs are known as edges, arcs, or lines for an undirected graph and as arrows, directed edges, directed arcs, or directed lines for a directed graph. The vertices may be part of the graph structure, or may be external entities represented by integer indices or references. [1]

Usage

The Graph class allows you to create nodes and edges and visualize the resulting graph. Edges can have direction which indicates parent-child relationship.

Graph: Constructing a New Graph

from abstract import Graph

graph = Graph()

add_node: Adding a New Node

The add_node method returns a GraphNode object.

node_order = [
    'scissors', 'paper', 'rock', 'lizard', 'Spock', 'scissors',
    'lizard', 'paper', 'Spock', 'rock', 'scissors'
]

# add nodes (avoid duplicates)
for node in set(node_order):
    node = graph.add_node(name=node)

connect: Adding Edges

The connect method creates an edge from a start node to an end node.

for index in range(len(node_order)-1):
    edge = graph.connect(start=node_order[index], end=node_order[index+1])

get_node

To retrieve a node from the graph you can use the get_node method.

rock = graph.get_node('rock')

draw (render)

The render method visualizes the graph and if a path is provided it saves it to an image file that can be a pdf or png. The file format is infered from the path argument. The draw method is just an alias for render.

# just visualize the graph
graph.draw()

https://raw.githubusercontent.com/greyli/flask-share/master/images/demo.png

# save as a png file and view the file
graph.draw(path='my_graph.png', view=True)

Future Features

• Create a graph from:
  • list of dictionaries
  • dataframe
• Create a new graph by filtering a graph