solves binary tree paths in python

Author: anishLearnsToCode

README.md

@@ -77,7 +77,7 @@
 | 246 | 🔒 [Strobogramatic Number](https://leetcode.com/problems/strobogrammatic-number) | Easy | |
 | 252 | 🔒 [Meeting Rooms](https://leetcode.com/problems/meeting-rooms) | Easy | |
 | 256 | 🔒 [Paint House](https://leetcode.com/problems/paint-house) | Easy | |
-| 257 | [Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/BinaryTreePaths.java) |
+| 257 | [Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/BinaryTreePaths.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/binary_tree_paths.py) |
 | 258 | [Add Digits](https://leetcode.com/problems/add-digits) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/AddDigits.java) |
 | 263 | [Ugly Number](https://leetcode.com/problems/ugly-number) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](src/UglyNumber.java) |
 | 266 | [Palindrome Permutation](https://leetcode.com/problems/palindrome-permutation) | Easy | |

python/binary_tree_paths.py

@@ -0,0 +1,28 @@
+from typing import List
+
+
+# Definition for a binary tree node.
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+
+class Solution:
+    def is_leaf_node(self, root: TreeNode) -> bool:
+        return root.left is None and root.right is None
+
+    def binary_tree_paths(self, root: TreeNode, current_path: str, results: List[str]):
+        if root is None:
+            return
+        if self.is_leaf_node(root):
+            results.append(f'{current_path}->{root.val}'[2:])
+            return
+        self.binary_tree_paths(root.left, f'{current_path}->{root.val}', results)
+        self.binary_tree_paths(root.right, f'{current_path}->{root.val}', results)
+
+    def binaryTreePaths(self, root: TreeNode) -> List[str]:
+        result = []
+        self.binary_tree_paths(root, '', results=result)
+        return result