Adding HelloGraph example

Author: elmar-hinz

HelloGraph/__init__.py

@@ -0,0 +1,45 @@
+# https://github.com/elmar-hinz/Python.Challenges
+from challenges import Challenge
+
+class HelloGraphChallenge(Challenge):
+    """
+        Given: Two nodes and a list of edges
+        Return: Graph between the nodes and it's weight
+    """
+
+    sample = '''
+        2
+        4
+        1->2:2
+        2->3:4
+        3->4:10
+        4->5:8
+        5->6:1
+    '''
+
+    expect = '''
+        2->3->4
+        14
+    '''
+
+    def build(self):
+        self.model.start = self.line_to_integer(0)
+        self.model.stop = self.line_to_integer(1)
+        self.model.graph = dict()
+        for edge in self.edges(2):
+            self.model.graph[edge.tail] = (edge.head, edge.weight)
+
+    def calc(self):
+        head = None
+        tail = self.model.start
+        self.result.graph = [tail]
+        self.result.weight = 0
+        while tail != self.model.stop:
+            self.result.weight += self.model.graph[tail][1]
+            tail = self.model.graph[tail][0]
+            self.result.graph.append(tail)
+
+    def format(self):
+        self.output = self.format_path(self.result.graph)
+        self.output += self.br
+        self.output += str(self.result.weight)

HelloGraph/challenge.py

@@ -0,0 +1,30 @@
+import unittest
+from HelloGraph.challenge import HelloGraphChallenge
+
+class HelloGraphTest(unittest.TestCase):
+
+    def setUp(self):
+        self.challenge = HelloGraphChallenge()
+
+    def test__init__(self):
+        self.assertIsInstance(self.challenge, HelloGraphChallenge)
+        self.assertIn('5->6', self.challenge.sample)
+        self.assertIn('2->3->4', self.challenge.expect)
+
+    def test_build(self):
+        self.challenge.read()
+        self.challenge.build()
+        self.assertEqual(2, self.challenge.model.start)
+        self.assertEqual(4, self.challenge.model.stop)
+        self.assertEqual(4, self.challenge.model.graph[3][0])
+        self.assertEqual(10, self.challenge.model.graph[3][1])
+
+    def test_format(self):
+        self.challenge.result.weight = 14
+        self.challenge.result.graph = [2, 3, 4]
+        self.challenge.format()
+        self.assertEqual(self.challenge.expectation(), self.challenge.output)
+
+    def test_full_integration(self):
+        self.challenge.main()
+        self.assertEqual(self.challenge.expectation(), self.challenge.output)