How to create a Binary Tree in Python?

# Binary tree node
class node:
     
    def __init__(self, data):
        self.left=None
        self.right=None
        self.data=data
  
# Function to create a new
# Binary node
def newNode(data):
    return node(data)

def t():
    root=newNode("A")
    root.left = newNode("B")
    root.right = newNode("C")
    root.left.left = newNode("D")
    root.left.right = newNode("G")
    root.right.right = newNode("E")
    root.right.right.left = newNode("F")
    

print(t)

Hi, I have tried to create a Binary Tree above but I did not managed to print out the binary tree when I print “t”. Instead of a Binary Tree, it shows me this:

Answer

Function t just creates a binary tree. If you want to print a tree you need to traverse it and print it. Depending on the way you want to print a tree, there are different traversal techniques, the popular of which are Inorder, Preorder and Postorder. Check this wiki link for tree traversal methods.

Your code has to be extended to do the required tree traversal. Sample is below:

# Binary tree node
class node:
     
    def __init__(self, data):
        self.left=None
        self.right=None
        self.data=data
  
# Function to create a new
# Binary node
def newNode(data):
    return node(data)

def t():
    root=newNode("A")
    root.left = newNode("B")
    root.right = newNode("C")
    root.left.left = newNode("D")
    root.left.right = newNode("G")
    root.right.right = newNode("E")
    root.right.right.left = newNode("F")
    return root


def in_order(root):
    if root:
        in_order(root.left)
        print (root.data)
        in_order(root.right) 

def pre_order(root):
    if root:
        print (root.data)
        pre_order(root.left)
        pre_order(root.right)
        
def post_order(root):
    if root:        
        post_order(root.left)
        post_order(root.right)
        print (root.data)
        
root = t()


print ("In Order")
in_order(root)
print ("Pre Order")
pre_order(root)
print ("Post Order")
post_order(root)

Output:

In Order
D
B
G
A
C
F
E
Pre Order
A
B
D
G
C
E
F
Post Order
D
G
B
F
E
C
A