Add Python

Author: LokiSharp

5.mergeSort.md

@@ -70,4 +70,30 @@ function merge(left, right)
 
     return result;
 }
-```
+```
+
+## 4. Python 代码实现
+
+```python
+def mergeSort(arr):
+    import math
+    if(len(arr)<2):
+        return arr
+    middle = math.floor(len(arr)/2)
+    left = arr[0:middle]
+    right = arr[middle:]
+    return merge(mergeSort(left), mergeSort(right))
+
+def merge(left,right):
+    result = []
+    while left and right:
+        if left[0] <= right[0]:
+            result.append(left.pop(0));
+        else:
+            result.append(right.pop(0));
+    while left:
+        result.append(left.pop(0));
+    while right:
+        result.append(right.pop(0));
+    return result
+```