solves sum left leaves in python

Author: anishLearnsToCode

README.md

@@ -107,7 +107,7 @@
 | 389 | [Find the Difference](https://leetcode.com/problems/find-the-difference) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/FindTheDifference.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/find_the_difference.py) |
 | 392 | [Is Subsequence](https://leetcode.com/problems/is-subsequence) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/IsSubsequence.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/is_subsequence.py) |
 | 401 | [Binary Watch](https://leetcode.com/problems/binary-watch) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/BinaryWatch.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/binary_watch.py) |
-| 404 | [Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/SumOfLeftLeaves.java) |
+| 404 | [Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/SumOfLeftLeaves.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/sum_of_left_leaves.py) |
 | 405 | [Convert a Number to Hexadecimal](https://leetcode.com/problems/convert-a-number-to-hexadecimal) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/ConvertNumberToHexadecimal.java) |
 | 408 | [Valid Word Abbreviation](https://leetcode.com/problems/valid-word-abbreviation) | Easy | |
 | 409 | [Longest Palindrome](https://leetcode.com/problems/longest-palindrome) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/LongestPalindrome.java) |

python/sum_of_left_leaves.py

@@ -0,0 +1,21 @@
+# 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 sum_left_leaves(self, root: TreeNode, is_left_branch: bool) -> int:
+        if root is None:
+            return 0
+        if self.is_leaf_node(root) and is_left_branch:
+            return root.val
+        return self.sum_left_leaves(root.left, is_left_branch=True) + self.sum_left_leaves(root.right, is_left_branch=False)
+
+    def sumOfLeftLeaves(self, root: TreeNode) -> int:
+        return self.sum_left_leaves(root, is_left_branch=False)