Decision Tree

decisiontree.py

@@ -0,0 +1,66 @@
+class Node(object):
+    pass
+
+def menu(prompt, decisions):
+    print("> %s" % prompt)
+    for i,decision in enumerate(decisions):
+        print("%d. %s" % (i,decision))
+    answer = int(input("Answer: "))
+    return answer
+
+class DecisionNode(Node):
+    def __init__(self, question):
+        self.question = question
+        self.decisions = []
+
+    def addDecision(self, response, node):
+        self.decisions.append( (response,node) )
+
+    def display(self):
+        i = menu(self.question, [ d[0] for d in self.decisions ])
+        return self.decisions[i][1]
+
+class AnswerNode(Node):
+    def __init__(self, answer):
+        self.answer = answer
+
+    def display(self):
+        print(self.answer)
+        return None
+
+
+if __name__ == "__main__":
+    high = AnswerNode("hohes Risiko")
+    medium = AnswerNode("mittleres Risiko")
+    low = AnswerNode("niedriges Risiko")
+
+    n6 = DecisionNode("Einkommen?")
+    n6.addDecision("0 Eur bis 15 Tsd Eur", high)
+    n6.addDecision("15 Tsd Eur bis 35 Tsd Eur", medium)
+    n6.addDecision("ueber 35 Tsd Eur", low)
+
+    n4 = DecisionNode("Sicherheiten?")
+    n4.addDecision("keine", n6)
+    n4.addDecision("angemessen", low)
+
+    n3 = DecisionNode("Verschuldung?")
+    n3.addDecision("hoch", n4)
+    n3.addDecision("niedrig", low)
+
+    n2 = DecisionNode("Sicherheiten?")
+    n2.addDecision("keine", high)
+    n2.addDecision("angemessen", medium)
+
+    n1 = DecisionNode("Verschuldung?")
+    n1.addDecision("hoch", high)
+    n1.addDecision("niedrig", n4)
+
+    n0 = DecisionNode("Kreditwuerdigkeit?")
+    n0.addDecision("unbekannt",n1)
+    n0.addDecision("schlecht",n2)
+    n0.addDecision("gut",n3)
+
+    node = n0
+
+    while node is not None:
+        node = node.display()