1 files changed, 40 insertions, 1 deletions
diff --git a/treelib/tree.py b/treelib/tree.py
index 7d92297..1cc9ac8 100644
--- a/treelib/tree.py
+++ b/treelib/tree.py
@@ -929,7 +929,7 @@ class Tree(object):
             print("Tree is empty")
 
         if stdout:
-            print(self._reader)
+            print(self._reader.encode("utf-8"))
         else:
             return self._reader
 
@@ -1128,3 +1128,42 @@ class Tree(object):
             print(f.getvalue())
 
         f.close()
+
+    @classmethod
+    def from_map(cls, child_parent_dict, id_func=None, data_func=None):
+        """
+        takes a dict with child:parent, and form a tree
+        """
+        tree = Tree()
+        if tree is None or tree.size() > 0:
+            raise ValueError("need to pass in an empty tree")
+        id_func = id_func if id_func else lambda x: x
+        data_func = data_func if data_func else lambda x: None
+        parent_child_dict = {}
+        root_node = None
+        for k, v in child_parent_dict.items():
+            if v is None and root_node is None:
+                root_node = k
+            elif v is None and root_node is not None:
+                raise ValueError("invalid input, more than 1 child has no parent")
+            else:
+                if v in parent_child_dict:
+                    parent_child_dict[v].append(k)
+                else:
+                    parent_child_dict[v] = [k]
+        if root_node is None:
+            raise ValueError("cannot find root")
+
+        tree.create_node(root_node, id_func(root_node), data=data_func(root_node))
+        queue = [root_node]
+        while len(queue) > 0:
+            parent_node = queue.pop()
+            for child in parent_child_dict.get(parent_node, []):
+                tree.create_node(
+                    child,
+                    id_func(child),
+                    parent=id_func(parent_node),
+                    data=data_func(child),
+                )
+                queue.append(child)
+        return tree