test for purge, copy, extract added

Author: yyl

unit3/doublyLinkedList.py

@@ -87,4 +87,32 @@ def purge(self):
     self._head = None
     self._tail = None
 
-
+  def extract(self, obj):
+    tmp = self._head
+    prev = tmp
+    while tmp != None:
+      if tmp._value == obj:
+        if tmp == self._head:
+          tmp._next._prev = None
+          self._head = tmp._next
+        elif tmp == self._tail:
+          tmp._prev = None
+          prev._next = None
+          self._tail = prev
+        else:
+          prev._next = tmp._next
+          tmp._prev = None
+          tmp._next._prev = prev
+          tmp._next = None
+        return obj
+      prev = tmp
+      tmp = tmp._next
+    return None
+
+  def __copy__(self):
+    tmp = DoublyLinkedList()
+    current = self._head
+    while current != None:
+      tmp.append(current.value)
+      current = current._next
+    return tmp

unit3/test.py

@@ -1,6 +1,7 @@
 import unittest
 from doublyLinkedList import DoublyLinkedList
 from opus7.exception import *
+from copy import copy
 
 class TestList(unittest.TestCase):
   def setUp(self):
@@ -41,6 +42,26 @@ def test_purge(self):
     self.assertEqual(self.l.head, None)
     self.assertEqual(self.l.tail, None)
 
+  def test_extract(self):
+    self.l.append(1)
+    self.l.append(2)
+    self.l.append(3)
+    self.l.append(4)
+    self.l.append(5)
+    self.assertEqual(self.l.extract(1), 1)
+    self.assertEqual(self.l.head.value, 2)
+    self.assertEqual(self.l.extract(10), None)
+    self.assertEqual(self.l.extract(5), 5)
+    self.assertEqual(self.l.tail.value, 4)
+
+  def test_copy(self):
+    self.l.append(1)
+    self.l.append(2)
+    self.l.append(3)
+    a = copy(self.l)
+    self.assertEqual(a.head.value, 1)
+    self.assertEqual(a.tail.value, 3)
+
 
 if __name__ == "__main__":
   unittest.main()