new_contents: class Node:
      def __init__(self, key):
          self.right = None
          self.left = None
          self.key = key
  
      def addLeftChild(self, node):
          self.left = node
  
      def addRightChild(self, node):
          self.right = node
  
  
  class BinaryTree:
      def getRootOfTree(self):
          root = Node(1)
          node2 = Node(2)
          node3 = Node(3)
          node4 = Node(4)
          node5 = Node(5)
          node6 = Node(6)
          node7 = Node(7)
          root.addLeftChild(node2)
          root.addRightChild(node3)
          node2.addLeftChild(node4)
          node2.addRightChild(node5)
          node3.addLeftChild(node6)
          node3.addRightChild(node7)
          return root
  
  
  def inorder(node, array):
      if node is None:
          return array
      array = inorder(node.left, array)
      array.append(node.key)
      return inorder(node.right, array)
  
  
  if __name__ == '__main__':
      # Create a Tree
      tree = BinaryTree()
      root = tree.getRootOfTree()
      # Print Inorder Traversal of Tree
      print 'Inorder traversal for binary tree:', inorder(root, [])
  
subject: Add binary tree in python