#1 removes if to use more polymorphism

taciogt · Sep 13, 2020 · 817a68a · 817a68a
1 parent 58ae125
commit 817a68a
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Showing 2 changed files with 22 additions and 13 deletions.
diff --git a/src/sequences/linked_list.py b/src/sequences/linked_list.py
@@ -40,12 +40,14 @@ def __iter__(self):
         return _NodeIterator(current_node=self)
 
     @property
-    def content(self):
-        raise AttributeError
+    @abstractmethod
+    def content(self) -> T:
+        ...
 
     @property
-    def next(self):
-        raise AttributeError
+    @abstractmethod
+    def next(self) -> _AbstractNode:
+        ...
 
 
 class _EmptyNode(_AbstractNode):
@@ -70,6 +72,14 @@ def __eq__(self, other):
     def __getitem__(self, _):
         raise IndexError
 
+    @property
+    def content(self):
+        raise AttributeError
+
+    @property
+    def next(self):
+        raise AttributeError
+
 
 class _Node(_AbstractNode):
     def __init__(self, content: T, *next_nodes: Sequence[T]):
@@ -125,13 +135,11 @@ def __len__(self):
             length += 1
         return length
 
-    def __str__(self):
-        if self.head is not _EmptyNode:
-            return f'{self.__class__.__name__}[{self.head}]'
-        else:
-            return f'{self.__class__.__name__}[]'
+    def __str__(self) -> str:
+        list_contents = ', '.join(map(str, self.head))
+        return f'{self.__class__.__name__}[{list_contents}]'
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return self.__str__()
 
     def __getitem__(self, item) -> Union[T, LinkedList]:
@@ -140,6 +148,7 @@ def include_index(index):
                 match_step = item.step is None or index % item.step == 0
                 should_stop = item.stop is not None and index >= item.stop
                 return item.start <= index and match_step and not should_stop
+
             if self.head is not None:
                 return LinkedList(*[node for index, node in enumerate(self.head)
                                     if include_index(index)])

diff --git a/src/sequences/test_linked_list.py b/src/sequences/test_linked_list.py
@@ -6,16 +6,16 @@
 class TestLinkedListBasicMethods(TestCase):
     def test_str(self):
         linked_list = LinkedList(1, 2, 3)
-        self.assertEqual(str(linked_list), 'LinkedList[Node(1)->Node(2)->Node(3)]')
+        self.assertEqual(str(linked_list), 'LinkedList[1, 2, 3]')
 
         linked_list = LinkedList(1)
-        self.assertEqual(str(linked_list), 'LinkedList[Node(1)]')
+        self.assertEqual(str(linked_list), 'LinkedList[1]')
 
         linked_list = LinkedList()
         self.assertEqual(str(linked_list), 'LinkedList[]')
 
         linked_list = LinkedList(None)
-        self.assertEqual(str(linked_list), 'LinkedList[Node(None)]')
+        self.assertEqual(str(linked_list), 'LinkedList[None]')
 
     def test_equality_with_same_type(self):
         self.assertEqual(LinkedList(), LinkedList())