Add function which calculates the Importance value.

Importance.py

+"""
+Provides a function to calculate the importance value of a task.
+
+For those who are familiar with the Toodledo website, the importance value is a
+combination of the priority and the todo's due date. Low priority tasks due
+today may have a higher importance than high priority tasks in the distant
+future.
+"""
+
+import Config
+
+IMPORTANCE_VALUE = {'A': 3, 'B': 2, 'C': 1}
+
+def importance(p_todo):
+    """
+    Calculates the importance of the given task.
+    """
+    result = 2
+
+    priority = p_todo.priority()
+    result += IMPORTANCE_VALUE[priority] if priority in IMPORTANCE_VALUE else 0
+
+    if p_todo.has_tag(Config.TAG_DUE):
+        days_left = p_todo.days_till_due()
+
+        if days_left >= 7 and days_left < 14:
+            result += 1
+        elif days_left >= 2 and days_left < 7:
+            result += 2
+        elif days_left >= 1 and days_left < 2:
+            result += 3
+        elif days_left >= 0 and days_left < 1:
+            result += 5
+        elif days_left < 0:
+            result += 6
+
+    if p_todo.has_tag(Config.TAG_STAR):
+        result += 1
+
+    return result

test/ImportanceTest.py

+import datetime
+import unittest
+
+import Config
+from Importance import importance
+import Todo
+
+class ImportanceTest(unittest.TestCase):
+    def test_importance1(self):
+        todo = Todo.Todo("Foo")
+        self.assertEqual(importance(todo), 2)
+
+    def test_importance2(self):
+        todo = Todo.Todo("(A) Foo")
+        self.assertEqual(importance(todo), 5)
+
+    def test_importance3(self):
+        todo = Todo.Todo("(A) Foo " + Config.TAG_STAR + ":1")
+        self.assertEqual(importance(todo), 6)
+
+    def test_importance4(self):
+        today_str = datetime.date.today().isoformat()
+        todo = Todo.Todo("(C) Foo " + Config.TAG_DUE + ":" + today_str)
+        self.assertEqual(importance(todo), 8)