Add Python

Author: LokiSharp

4.shellSort.md

@@ -40,4 +40,25 @@ function shellSort(arr) {
     }
     return arr;
 }
-```
+```
+
+## 2. Python 代码实现
+
+```python
+def shellSort(arr):
+    import math
+    gap=1
+    while(gap < len(arr)/3):
+        gap = gap*3+1
+    while gap > 0:
+        for i in range(gap,len(arr)):
+            temp = arr[i]
+            j = i-gap
+            while j >=0 and arr[j] > temp:
+                arr[j+gap]=arr[j]
+                j-=gap
+            arr[j+gap] = temp
+        gap = math.floor(gap/3)
+    return arr
+}
+```