Add tests for expand_tree

docs/source/index.rst

@@ -8,18 +8,21 @@ Welcome to treelib's documentation!
 
 **Redistributed under Apache License (2.0) since version 1.3.0.**
 
-`Tree data structure <http://en.wikipedia.org/wiki/Tree_%28data_structure%29>`_
-is an important data structure in computer programming languages. It has
-important applications where hierarchical data connections are present such as
-computer folder structure and decision-tree algorithm in Machine Learning. Thus
-`treelib <https://github.com/caesar0301/pyTree>`_ is created to provide an
+`Tree data structure
+<http://en.wikipedia.org/wiki/Tree_%28data_structure%29>`_ is an
+important data structure in computer programming languages. It has
+wide applications with hierarchical data connections say file systems
+and some algorithms in Machine Learning. `treelib
+<https://github.com/caesar0301/pyTree>`_ is created to provide an
 efficient implementation of tree data structure in Python.
 
 The main features of `treelib` includes:
 
 	* Simple to use in both python 2 and 3.
 	* Efficient operation of node indexing with the benefit of dictionary type.
-	* Support various tree operations like **traversing**, **insertion**, **deletion**, **node moving**, **shallow/deep copying**, **subtree cutting** etc.
+   * Support common tree operations like **traversing**,
+     **insertion**, **deletion**, **node moving**, **shallow/deep
+     copying**, **subtree cutting** etc.
 	* Support user-defined data payload to accelerate your model construction.
 	* Has pretty tree showing and text/json dump for pretty show and offline analysis.
 

docs/source/pyapi.rst

@@ -4,17 +4,18 @@ Useful APIs
 .. module:: treelib
     :synopsis: Tree data structure in Python.
 
-This `treelib` is a simple module containing only two classes: ``Node`` and
-``Tree``. Tree is a self-contained structure with some nodes and connected by
-branches. One tree has and only has one root, while a node (except root) has
-several children and merely one parent.
-
-*Note:* To solve the string compatibility between Python 2.x and 3.x, treelib
-follows the way of porting Python 3.x to 2/3. That means, all strings are
-manipulated as unicode and you do not need `u''` prefix anymore. The impacted
-functions include `str()`, `show()` and `save2file()` routines. But if your
-data contains non-ascii characters and Python 2.x is used, you have to trigger
-the compatibility by declaring `unicode_literals` in the code:
+`treelib` is a Python module with two primary classes: ``Node`` and
+``Tree``. Tree is a self-contained structure with some nodes and
+connected by branches. A tree owns merely a root, while a
+node (except root) has some children and one parent.
+
+*Note:* To solve string compatibility between Python 2.x and 3.x,
+treelib follows the way of porting Python 3.x to 2/3. That means, all
+strings are manipulated as unicode and you do not need `u''` prefix
+anymore. The impacted functions include `str()`, `show()` and
+`save2file()` routines. But if your data contains non-ascii
+characters and Python 2.x is used, you have to trigger the
+compatibility by declaring `unicode_literals` in the code:
 
 .. code-block:: sh
 
@@ -192,8 +193,10 @@ Instance attributes:
 
     Traverse the tree nodes with different modes. ``nid`` refers to the
     expanding point to start; ``mode`` refers to the search mode (Tree.DEPTH,
-    Tree.WIDTH); ``filter`` refers to the function of one variable to act on
-    the :class:`Node` object; ``key``, ``reverse`` are present to sort
+    Tree.WIDTH). ``filter`` refers to the function of one variable to act on
+    the :class:`Node` object. In this manner, the traversing will not continue to
+    following children of node whose condition does not pass the filter.
+    ``key``, ``reverse`` are present to sort
     :class:Node objects at the same level.
 
 
@@ -281,11 +284,13 @@ Instance attributes:
 
     Print the tree structure in hierarchy style. ``nid`` refers to the
     expanding point to start; ``level`` refers to the node level in the tree
-    (root as level 0); ``idhidden`` refers to hiding the node ID when printing;
+    (root as level 0).
+    ``idhidden`` refers to hiding the node ID when printing.
     ``filter`` refers to the function of one variable to act on the
-    :class:`Node` object; ``key``, ``reverse`` are present to sort
-    :class:`Node` object in the same level. ``data_property`` refers to the property
-    on the node data object to be printed.
+    :class:`Node` object.  In this manner, the traversing will not continue to
+    following children of node whose condition does not pass the filter.
+    ``key``, ``reverse`` are present to sort :class:`Node` object in the same level.
+    ``data_property`` refers to the property on the node data object to be printed.
 
     You have three ways to output your tree data, i.e., stdout with ``show()``,
     plain text file with ``save2file()``, and json string with ``to_json()``. The

tests/test_treelib.py

@@ -218,7 +218,10 @@ def test_expand_tree(self):
         self.assertEqual(len(nodes), 2)
         nodes = [nid for nid in self.tree.expand_tree(mode=Tree.WIDTH)]
         self.assertEqual(nodes, [u'h\xe1rry', u'bill', u'jane', u'george', u'diane'])
-        nodes = [nid for nid in self.tree.expand_tree(filter = lambda x: x.tag == "Diane")]
+        nodes = [nid for nid in self.tree.expand_tree(filter = lambda x: x.tag == "Bill")]
+        self.assertEqual(len(nodes), 0)
+        nodes = [nid for nid in self.tree.expand_tree(filter = lambda x: x.tag != "Bill")]
+        self.assertEqual(nodes, [u'h\xe1rry', u'jane', u'diane'])
 
     def test_move_node(self):
         diane_parent = self.tree.parent("diane")

treelib/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '1.3.5'
+__version__ = '1.3.6'
 
 from .tree import Tree
 from .node import Node

treelib/tree.py

@@ -246,29 +246,6 @@ def __update_fpointer(self, nid, child_id, mode):
     def __real_true(self, p):
         return True
 
-    def to_dict(self, nid=None, key=None, sort=True, reverse=False, with_data=False):
-        """transform self into a dict"""
-
-        nid = self.root if (nid is None) else nid
-        ntag = self[nid].tag
-        tree_dict = {ntag: {"children": []}}
-        if with_data:
-            tree_dict[ntag]["data"] = self[nid].data
-
-        if self[nid].expanded:
-            queue = [self[i] for i in self[nid].fpointer]
-            key = (lambda x: x) if (key is None) else key
-            if sort:
-                queue.sort(key=key, reverse=reverse)
-
-            for elem in queue:
-                tree_dict[ntag]["children"].append(
-                    self.to_dict(elem.identifier, with_data=with_data, sort=sort, reverse=reverse))
-            if len(tree_dict[ntag]["children"]) == 0:
-                tree_dict = self[nid].tag if not with_data else \
-                            {ntag: {"data":self[nid].data}}
-            return tree_dict
-
     def add_node(self, node, parent=None):
         """
         Add a new node to tree.
@@ -349,7 +326,8 @@ def expand_tree(self, nid=None, mode=DEPTH, filter=None, key=None,
         Brian J. Reiser, page 239-241
 
         UPDATE: the @filter function is performed on Node object during
-        traversing.
+        traversing. In this manner, the traversing will not continue to
+        following children of node whose condition does not pass the filter.
 
         UPDATE: the @key and @reverse are present to sort nodes at each
         level.
@@ -710,5 +688,28 @@ def to_json(self, with_data=False, sort=True, reverse=False):
         """Return the json string corresponding to self"""
         return json.dumps(self.to_dict(with_data=with_data, sort=sort, reverse=reverse))
 
+    def to_dict(self, nid=None, key=None, sort=True, reverse=False, with_data=False):
+        """transform self into a dict"""
+
+        nid = self.root if (nid is None) else nid
+        ntag = self[nid].tag
+        tree_dict = {ntag: {"children": []}}
+        if with_data:
+            tree_dict[ntag]["data"] = self[nid].data
+
+        if self[nid].expanded:
+            queue = [self[i] for i in self[nid].fpointer]
+            key = (lambda x: x) if (key is None) else key
+            if sort:
+                queue.sort(key=key, reverse=reverse)
+
+            for elem in queue:
+                tree_dict[ntag]["children"].append(
+                    self.to_dict(elem.identifier, with_data=with_data, sort=sort, reverse=reverse))
+            if len(tree_dict[ntag]["children"]) == 0:
+                tree_dict = self[nid].tag if not with_data else \
+                            {ntag: {"data":self[nid].data}}
+            return tree_dict
+
 if __name__ == '__main__':
     pass