Add source code of Recently Used List Kata in Python

Src/py/Recently Used List/rul.py

@@ -0,0 +1,16 @@
+class RecentlyUsedList:
+    def __init__(self):
+        self._list = []
+
+    def __len__(self):
+        return len(self._list)
+
+    def insert(self, item):
+        try:
+            self._list.remove(item)
+        except ValueError:
+            pass
+        self._list.insert(0, item)
+
+    def __getitem__(self, index):
+        return self._list[index]

Src/py/Recently Used List/test_rul.py

@@ -0,0 +1,29 @@
+import unittest
+from rul import RecentlyUsedList
+
+class RecentlyUsedListTests(unittest.TestCase):
+    def test_creating_a_new_list(self):
+        rul = RecentlyUsedList()
+        self.assertEqual(len(rul), 0)
+
+    def test_inserting_an_item(self):
+        rul = RecentlyUsedList()
+        item = 'item'
+        rul.insert(item)
+        self.assertEqual(len(rul), 1)
+        self.assertEqual(rul[0], item)
+
+    def test_inserting_two_unique_items(self):
+        rul = RecentlyUsedList()
+        rul.insert('first')
+        most_recent_item = 'second'
+        rul.insert(most_recent_item)
+        self.assertEqual(rul[0], most_recent_item)
+
+    def test_inserting_a_duplicate(self):
+        rul = RecentlyUsedList()
+        duplicate = 'b'
+        for item in 'a', duplicate, 'c', duplicate:
+            rul.insert(item)
+        self.assertEqual(len(rul), 3)
+        self.assertEqual(rul[0], duplicate)