diff --git a/Python/left-and-right-sum-differences.py b/Python/left-and-right-sum-differences.py
new file mode 100644
index 0000000000..90b469fe2e
--- /dev/null
+++ b/Python/left-and-right-sum-differences.py
@@ -0,0 +1,17 @@
+# Time:  O(n)
+# Space: O(1)
+
+# prefix sum
+class Solution(object):
+    def leftRigthDifference(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+        total = sum(nums)
+        result = []
+        curr = 0
+        for x in nums:
+            curr += x
+            result.append(abs((curr-x)-(total-curr)))
+        return result