Binary Tree

#Binary Tree
from collections import deque
class Node:
    def __init__(self,val):
        self.data=val
        self.rchild=None
        self.lchild=None
class BinaryTree:
    def __init__(self):
        self.root=None

    def isempty(self):
        return self.root==None

    def display(self):
        self.display1(self.root,0)
        print()
    def display1(self,p,level):
        if p is None:
            return
        self.display1(p.rchild,level+1)
        print()
        for i in range(level):
            print(" ",end='')
        print(p.data)
        self.display1(p.lchild,level+1)

    def pre(self):
        self.preorder(self.root)
        print()
    def preorder(self,p):
        if p is None:
            return
        print(p.data," ",end='')
        self.preorder(p.lchild)
        self.preorder(p.rchild)

    def inn(self):
        self.inorder(self.root)
        print()
    def inorder(self,p):
        if p is None:
            return
        self.inorder(p.lchild)
        print(p.data," ",end='')
        self.inorder(p.rchild)

    def post(self):
        self.postorder(self.root)
        print()
    def postorder(self,p):
        if p is None:
            return
        self.postorder(p.lchild)
        self.postorder(p.rchild)
        print(p.data," ",end='')

    def level(self):
        if self.root is None:
            print("Tree is empty!!")
        qu=deque()
        qu.append(self.root)
        while len(qu)!=0:
            p=qu.pop()
            print(p.data," ",end='')
            if p.lchild is not None:
                qu.append(p.lchild)
            if p.rchild is not None:
                qu.append(p.rchild)

    def height(self):
        return self.height1(self.root)

    def height1(self,p):
        if p is None:
            return 0
        hl=self.height1(p.lchild)
        hr=self.height1(p.rchild)

        if hl > hr:
            return(1+hl)
        else:
            return(1+hr)

    def create(self):
        self.root=Node('A')
        self.root.lchild=Node('B')
        self.root.rchild=Node('C')
        self.root.lchild.lchild=Node('D')
        self.root.lchild.rchild=Node('E')
        self.root.rchild.rchild=Node('F')

BT=BinaryTree()
BT.create()

BT.display()

print("PREORDER: ")
BT.pre()
print()

print("INORDER: ")
BT.inn()
print()

print("POSTORDER: ")
BT.post()
print()

print("LEVELS: ")
BT.level()
print()

print("HEIGHT: ")
BT.height()
print()