solves invert a binary tree in python

Author: anishLearnsToCode

Diff for: README.md

@@ -64,7 +64,7 @@
 | 217 | [Contains Duplicate](https://leetcode.com/problems/contains-duplicate) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/ContainsDuplicate.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/contains_duplicate.py) |
 | 219 | [Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/ContainsDuplicateII.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/contains_duplicate_ii.py) |
 | 225 | [Implement Stack using Queues](https://leetcode.com/problems/implement-stack-using-queues) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/MyStack.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/implement_stack_using_queues.py) |
-| 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/InvertBinaryTree.java) |
+| 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/InvertBinaryTree.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/invert_binary_tree.py) |
 | 231 | [Power of Two](https://leetcode.com/problems/power-of-two) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/PowerOf2.java) |
 | 232 | [Implement Queue Using Stacks]() | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/MyQueue.java) | 
 | 234 | [Palindrome Linked Lists](https://leetcode.com/problems/palindrome-linked-list) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/PalindromeLinkedList.java) | 

Diff for: python/invert_binary_tree.py

@@ -0,0 +1,17 @@
+# Definition for a binary tree node.
+from typing import Optional
+
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def invertTree(self, root: TreeNode) -> Optional[TreeNode]:
+        if root is None:
+            return None
+        root.left, root.right = self.invertTree(root.right), self.invertTree(root.left)
+        return root