### Python 3 code to find the Lowest Common Ancestor of a Binary Search Tree

```
def lowestCommonAncestor(root, p, q):
"""
:type root: TreeNode
:type p: TreeNode
:type q: TreeNode
:rtype: TreeNode
"""
if root is None or p is None or q is None:
return None
if p.val > q.val:
temp = p
p = q
q = temp
current_node = root
while current_node:
if p.val <= current_node.val and current_node.val <= q.val:
return current_node
else:
current_node = current_node.left if p.val < current_node.val else current_node.right
return None
```

Hope it helps.