Create binaryTree.py

Implementation of Binary Tree.
Input:
1. Tree Size
2. Node Values

Output:
Returns In-order, Pre-order, Post-order and Level-order Binary Tree.

binaryTree.py

@@ -0,0 +1,110 @@
+"""
+This is pure python implementation of tree traversal algorithms
+"""
+from __future__ import print_function
+import Queue
+import sys
+
+class TreeNode:
+    def __init__(self, data):
+        self.data = data
+        self.right = None
+        self.left = None
+
+
+def build_tree(size):
+    print("Enter the value of the root node: ", end=' ')
+    data = eval(input_function())
+
+    if data < 0:
+        return None
+    else:
+		q = Queue.Queue()
+		tree_node = TreeNode(data)
+		q.put(tree_node)
+		current_size = q.qsize()
+		while not q.empty() and current_size < size:
+			current_size = q.qsize()
+			node_found = q.get()
+			print("Enter the left node of %s: " % node_found.data, end=' ')
+			left_data = eval(input_function())
+			if left_data >= 0:
+				left_node = TreeNode(left_data)
+				node_found.left = left_node
+				q.put(left_node)
+			print("Enter the right node of %s: " % node_found.data, end=' ')
+			right_data = eval(input_function())
+			if right_data >= 0:
+				right_node = TreeNode(right_data)
+				node_found.right = right_node
+				q.put(right_node)
+    return tree_node
+
+
+def pre_order(node):
+    if not isinstance(node, TreeNode) or not node:
+        return
+    print(node.data, end=" ")
+    pre_order(node.left)
+    pre_order(node.right)
+
+
+def in_order(node):
+    if not isinstance(node, TreeNode) or not node:
+        return
+    in_order(node.left)
+    print(node.data, end=" ")
+    in_order(node.right)
+
+
+def post_order(node):
+    if not isinstance(node, TreeNode) or not node:
+        return
+    post_order(node.left)
+    post_order(node.right)
+    print(node.data, end=" ")
+
+
+def level_order(node):
+    if not isinstance(node, TreeNode) or not node:
+        return
+    q = Queue.Queue()
+    q.put(node)
+    while not q.empty():
+        node_dequeued = q.get()
+        print(node_dequeued.data, end=' ')
+        if node_dequeued.left:
+            q.put(node_dequeued.left)
+        if node_dequeued.right:
+            q.put(node_dequeued.right)
+
+
+if __name__ == '__main__':
+	# For python 2.x and 3.x compatibility: 3.x has not raw_input builtin
+    # otherwise 2.x's input builtin function is too "smart"
+	if sys.version_info.major < 3:
+		input_function = raw_input
+	else:
+		input_function = input	
+	print("Enter the size of Tree: ", end=' ')
+	treeSize = eval(input_function())
+	print("Tree size:", treeSize)
+	print("\n********* Binary Tree Traversals ************\n")
+
+
+	node = build_tree(treeSize)
+	print("\n********* Pre Order Traversal ************")
+	pre_order(node)
+	print("\n******************************************\n")
+
+	print("\n********* In Order Traversal ************")
+	in_order(node)
+	print("\n******************************************\n")
+
+	print("\n********* Post Order Traversal ************")
+	post_order(node)
+	print("\n******************************************\n")
+
+	print("\n********* Level Order Traversal ************")
+	level_order(node)
+	print("\n******************************************\n")