SDAG2 - Python Simple Directed Acyclic Graph

The Python Simple Directed Graph whith Cicle Detector and TopoloGical sorter utilities.

Project Home Page

This project was be hosted on Github.

Authors

• Moises P. Sena

Install

Install it using the Python PIP Project.

pip install sdag2

Scripts

tsort.py

Sources from Standard Input:

echo -e 'C A\nA B\nB D\nC D' | tsort.py

Sources from another file:

echo -e 'C A\nA B\nB D\nC D' > verticies.txt
tsort.py verticies.txt

More Options:

tsort.py --help
Usage: tsort.py [options] [FILE [OUT_FILE]]

Options:
  -h, --help            show this help message and exit
  -f FILE, --file=FILE  With no FILE, or when FILE is -, read standard input.
  -o OUT_FILE, --out-file=OUT_FILE
                        Write result to OUT_FILE, default is standard output.
  -s SEP, --separator=SEP
                        Items separator, default is \s regex.
  -q QUIT_SEQ, --quit-sequence=QUIT_SEQ
                        Stop read FILE where line equals QUIT_SEQ, default is
                        :quit.

Tests

import unittest
from sdag2 import DAG, CycleDetectedException

class DAGTest(unittest.TestCase):
    def test_simple(self):
        '''
        Tests the verticles order in:

        C --> A --> B --> D
        '''

        dag = DAG()
        a = dag.add("A")
        b = dag.add("B")
        c = dag.add("C")
        d = dag.add("D")

        dag.add_edge(c, a)
        dag.add_edge(a, b)
        dag.add_edge(b, d)
        dag.add_edge(c, d)

        rs = dag.topologicaly()

        self.assertTrue(rs.index("C") < rs.index("A"))
        self.assertTrue(rs.index("A") < rs.index("B"))
        self.assertTrue(rs.index("B") < rs.index("D"))
        self.assertTrue(rs.index("C") < rs.index("D"))

    def test_cicle_detect(self):
        '''
        Tests the verticles order in:

        C --> A --> B --> D -> C
        '''

        dag = DAG()
        a = dag.add("A")
        b = dag.add("B")
        c = dag.add("C")
        d = dag.add("D")

        dag.add_edge(c, a)
        dag.add_edge(a, b)
        dag.add_edge(b, d)
        dag.add_edge(c, d)

        try:
            # add cicle at A --> C --> A
            dag.add_edge(a, c)
            raise Exception("Cycle not detected")
        except CycleDetectedException: pass

def main():
    unittest.main()

if __name__ == "__main__":
    main()