graph demo

hbui

2024-07-17 cba010a56235c1c55976ca1986bbf982933619c2

graph demo

 stundenplan/Readme.md

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Beispielanwendung von Graph

 stundenplan/pyproject.toml

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[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[project]
name = "stundenplan"
version = "0.0.1"

[tool.setuptools.packages.find]
# All the following settings are optional:
where = ["src"]

# [project.scripts]
# To be done
# ttgeo = "turtlegeo.main:main"


 stundenplan/src/pygraph/__init__.py

 stundenplan/src/pygraph/graphdemo.py

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class Graph:
    def __init__(self):
        self.adjacent: dict[int, set] = {}
        self.vertex_attribute: dict[int, dict] = {}

    def add_vertex(self, vertex):
        if vertex not in self.adjacent:
            if not isinstance(vertex, int):
                raise TypeError(f"Argument {vertex} is not a valid vertex")
            self.adjacent[vertex] = set()

        pass

    def add_edge(self, u, v):
        self.add_vertex(u)
        self.add_vertex(v)
        v_neighbor = self.adjacent[v]
        if u not in v_neighbor:
            v_neighbor.add(u)
        u_neighbor = self.adjacent[u]
        if v not in u_neighbor:
            u_neighbor.add(v)
        pass

    def merge_attribute(self, vertex: int, properties: dict):
        """
        merge a dict of attribute to a vertex. Usage example:
        ```
        g = Graph();
        g.add_vertex(1);
        g.mergeAttribute(1, {'color': 0});
        ```
        :param vertex:
        :param properties:
        :return: self
        """
        if vertex not in self.adjacent:
            raise ValueError(f"Graph does not include vertex {vertex}")
        old_attributes = self.vertex_attribute[vertex]
        self.vertex_attribute[vertex] = old_attributes | properties
        return self
        pass

    def get_attribute(self, vertex):
        if vertex in self.adjacent:
            return self.vertex_attribute[vertex]
        else:
            raise ValueError(f"Graph does not include vertex {vertex}")
        pass

    def vertices(self):
        return self.adjacent.keys()

    def for_each_vertices(self, action):
        for v in self.vertices():
            action(v)

    def adjacent_of(self, vertex):
        if vertex not in self.adjacent:
            raise ValueError(f"Graph does not include vertex {vertex}")
        return self.adjacent.get(vertex)

    def for_each_edges(self, action):
        visited_edges: dict[int, set] = {}
        for start in self.vertices():
            for end in self.adjacent_of(start):
                (first, second) = (start, end) if (start > end) else (end, start)
            if first in visited_edges:
                visited_adjacent = visited_edges.get(first)
                if second not in visited_adjacent:
                    visited_adjacent.add(second)
                    action(start, end)
            else:
                adjacent = set()
                visited_edges[first] = adjacent
                adjacent.add(second)
                action(start, end)

    def __repr__(self):
        text = ""
        sorted_key = sorted(self.adjacent.keys())
        last_key = sorted_key.pop()
        def adjacent_fn(vertex): return "[" + ", ".join( [str(v) for v in self.adjacent[vertex]] ) + "]"
        for key in sorted_key:
            text += f"{key} → {adjacent_fn(key)}\n"
        text += f"{last_key} → {adjacent_fn(last_key)}"
        return text


 stundenplan/tests/__init__.py

 stundenplan/tests/pygraph/__init__.py

 stundenplan/tests/pygraph/graphdemo.tests.py

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import unittest

from pygraph.graphdemo import Graph


class GraphTestCase(unittest.TestCase):
    def test_construct_a_graph(self):
        g = Graph()
        g.add_edge(1, 2)
        g.add_edge(1, 3)
        g.add_edge(2, 3)
        g.add_edge(2, 4)
        txt = str(g)
        expected = '''1 → [2, 3]
2 → [1, 3, 4]
3 → [1, 2]
4 → [2]'''
        self.assertEqual(expected, txt)
        vertices = [1, 2, 3, 4]
        # def action(v): self.assertTrue(v in vertices)
        g.for_each_vertices(lambda v : self.assertTrue(v in vertices))

    def test_iterate_all_edges(self):
        g = Graph()
        g.add_edge(1, 2)
        g.add_edge(1, 3)
        g.add_edge(2, 3)
        g.add_edge(2, 4)
        edges = [
            "1-2", "1-3", "2-3", "2-4"
        ]
        def action(a, b):
            (s,e) = (a,b) if a < b else (b,a)
            edge = f"{s}-{e}"
            self.assertTrue(edge in edges)
        g.for_each_edges(action)


if __name__ == '__main__':
    unittest.main()