Recursive Method- TC is O(n log n) and SC is O(1)

def preOrder(root):

if root is not None:
    print(root.info,end=" ")
    preOrder(root.left)
    preOrder(root.right)

Iterative Method- TC is O(n) and SC is O(1)

def preOrder(root):

stack= [root]
result = []

if root is None:return []

while stack:
    root = stack.pop()
    result.append(root.info)
    if root.right:
        stack.append(root.right)
    if root.left :
        stack.append(root.left)
print (*result)