Refactor get_parent_node to get_parent and add pytest.ini

.gitignore

@@ -87,4 +87,4 @@ ENV/
 
 # Rope project settings
 .ropeproject
-.idea*
+.idea/

.travis.yml

@@ -9,7 +9,8 @@ matrix:
       dist: xenial
       sudo: true
 install:
-    - pip install flake8 mock
+    - pip install flake8
+    - pip install mock
     - pip install pytest==3.5.1
     - pip install pytest-cov==2.5.1
     - pip install python-coveralls==2.9.1

README.rst

@@ -50,7 +50,7 @@ Announcements
 Requirements
 ============
 
-- Python 2.7, 3.4, 3.5, 3.6, 3.7, 3.8
+- Python 2.7+ or 3.4+
 
 Installation
 ============

binarytree/__init__.py

@@ -1,6 +1,6 @@
 from __future__ import absolute_import, unicode_literals, division
 
-__all__ = ['Node', 'tree', 'bst', 'heap', 'build']
+__all__ = ['Node', 'tree', 'bst', 'heap', 'build', 'get_parent']
 
 import heapq
 import random
@@ -26,7 +26,7 @@ def _is_balanced(root):
     """Return the tree height + 1 if balanced, -1 otherwise.
 
     :param root: Root node of the binary tree.
-    :type root: binarytree.Node | None
+    :type root: binarytree.Node
     :return: Height if the binary tree is balanced, -1 otherwise.
     :rtype: int
     """
@@ -45,7 +45,7 @@ def _is_bst(root, min_value=float('-inf'), max_value=float('inf')):
     """Check if the binary tree is a BST (binary search tree).
 
     :param root: Root node of the binary tree.
-    :type root: binarytree.Node | None
+    :type root: binarytree.Node
     :param min_value: Minimum node value seen.
     :type min_value: int | float
     :param max_value: Maximum node value seen.
@@ -66,7 +66,7 @@ def _is_symmetric(root):
     """Check if the binary tree is symmetric.
 
     :param root: Root node of the binary tree.
-    :type root: binarytree.Node | None
+    :type root: binarytree.Node
     :return: True if the binary tree is symmetric, False otherwise.
     :rtype: bool
     """
@@ -168,7 +168,7 @@ def _build_tree_string(root, curr_index, index=False, delimiter='-'):
     call then combines its left and right sub-boxes to build a larger box etc.
 
     :param root: Root node of the binary tree.
-    :type root: binarytree.Node | None
+    :type root: binarytree.Node
     :param curr_index: Level-order_ index of the current node (root node is 0).
     :type curr_index: int
     :param index: If set to True, include the level-order_ node indexes using
@@ -247,7 +247,7 @@ def _get_tree_properties(root):
     """Inspect the binary tree and return its properties (e.g. height).
 
     :param root: Root node of the binary tree.
-    :rtype: binarytree.Node
+    :type root: binarytree.Node
     :return: Binary tree properties.
     :rtype: dict
     """
@@ -321,54 +321,54 @@ def _get_tree_properties(root):
     }
 
 
-def get_parent_node(root, node):
-    """Search from the binary tree and return the parent node for require node.
+def get_parent(root, child):
+    """Search the binary tree and return the parent of given child.
 
     :param root: Root node of the binary tree.
+    :type: binarytree.Node
+    :param child: Child node.
     :rtype: binarytree.Node
-    :param node: Require node you want to get its parent node.
-    :rtype: binarytree.Node
-    :return: The parent node of require node.
+    :return: Parent node, or None if missing.
     :rtype: binarytree.Node
 
     **Example**:
 
-        .. doctest::
+    .. doctest::
 
-            >>> from binarytree import Node, get_parent_node
-            >>> root = Node(0)
-            >>> root.left = Node(1)
-            >>> root.right = Node(2)
-            >>> root.left.left = Node(3)
-            >>> print (root)
-            >>>     0
-                   / \
-                  1   2
-                 /
-                3
-            >>> print (get_parent_node(root, root.left.left))
-            >>>   1
-                 /
-                3
+        >>> from binarytree import Node, get_parent
+        >>>
+        >>> root = Node(1)
+        >>> root.left = Node(2)
+        >>> root.right = Node(3)
+        >>> root.left.right = Node(4)
+        >>>
+        >>> print(root)
+        <BLANKLINE>
+          __1
+         /   \\
+        2     3
+         \\
+          4
+        <BLANKLINE>
+        >>> print(get_parent(root, root.left.right))
+        <BLANKLINE>
+        2
+         \\
+          4
+        <BLANKLINE>
     """
-    if node is None:
+    if child is None:
         return None
-    node_stack = []
-    while True:
-        if root is not None:
-            node_stack.append(root)
-            if root.left is node:
-                return root
-            else:
-                root = root.left
-        elif len(node_stack) > 0:
-            root = node_stack.pop()
-            if root.right is node:
-                return root
+
+    stack = [root]
+    while stack:
+        node = stack.pop()
+        if node:
+            if node.left is child or node.right is child:
+                return node
             else:
-                root = root.right
-        else:
-            break
+                stack.append(node.left)
+                stack.append(node.right)
     return None
 
 
@@ -383,9 +383,9 @@ class Node(object):
     :param value: Node value (must be a number).
     :type value: int | float | numbers.Number
     :param left: Left child node (default: None).
-    :type left: binarytree.Node | None
+    :type left: binarytree.Node
     :param right: Right child node (default: None).
-    :type right: binarytree.Node | None
+    :type right: binarytree.Node
     :raise binarytree.exceptions.NodeTypeError: If left or right child node is
         not an instance of :class:`binarytree.Node`.
     :raise binarytree.exceptions.NodeValueError: If node value is not a number

binarytree/version.py

@@ -1 +1 @@
-__version__ = '5.0.0'  # pragma: no cover
+__version__ = '5.1.0'  # pragma: no cover

docs/index.rst

@@ -11,7 +11,7 @@ algorithms. Heaps and BSTs (binary search trees) are also supported.
 Requirements
 ============
 
-- Python 2.7, 3.5, 3.6, 3.7, 3.8
+- Python 2.7+ or 3.4+
 
 Installation
 ============

docs/specs.rst

@@ -9,6 +9,7 @@ functions:
 * :func:`binarytree.tree`
 * :func:`binarytree.bst`
 * :func:`binarytree.heap`
+* :func:`binarytree.get_parent`
 
 Class: binarytree.Node
 ======================
@@ -38,3 +39,8 @@ Function: binarytree.heap
 =========================
 
 .. autofunction:: binarytree.heap
+
+Function: binarytree.get_parent
+===============================
+
+.. autofunction:: binarytree.get_parent

pytest.ini

@@ -0,0 +1,4 @@
+[pytest]
+python_files = tests.py test_*.py *_tests.py
+addopts = -vv -p no:warnings --cov=binarytree
+norecursedirs = venv htmlcov build dist .idea .git

tests/test_tree.py

@@ -6,7 +6,7 @@
 import pytest
 
 from binarytree import Node, build, tree, bst, heap
-from binarytree import get_parent_node
+from binarytree import get_parent
 from binarytree.exceptions import (
     NodeValueError,
     NodeIndexError,
@@ -887,18 +887,18 @@ def test_heap_float_values():
             assert root.size == root_copy.size
 
 
-@pytest.mark.order14
-def test_get_parent_node():
+def test_get_parent():
     root = Node(0)
     root.left = Node(1)
     root.right = Node(2)
     root.left.left = Node(3)
     root.right.right = Node(4)
-    assert get_parent_node(root, root.left.left) == root.left
-    assert get_parent_node(root, root.left) == root
-    assert get_parent_node(root, root) is None
-    assert get_parent_node(root, root.right.right) == root.right
-    assert get_parent_node(root, root.right) == root
-    assert get_parent_node(root, Node(5)) is None
-    assert get_parent_node(None, root.left) is None
-    assert get_parent_node(root, None) is None
+
+    assert get_parent(root, root.left.left) == root.left
+    assert get_parent(root, root.left) == root
+    assert get_parent(root, root) is None
+    assert get_parent(root, root.right.right) == root.right
+    assert get_parent(root, root.right) == root
+    assert get_parent(root, Node(5)) is None
+    assert get_parent(None, root.left) is None
+    assert get_parent(root, None) is None