Update 0056.合并区间.md

Added python version code

problems/0056.合并区间.md

@@ -168,7 +168,21 @@ class Solution {
 ```
 
 Python：
-
+```python
+class Solution:
+    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
+        if len(intervals) == 0: return intervals
+        intervals.sort(key=lambda x: x[0])
+        result = []
+        result.append(intervals[0])
+        for i in range(1, len(intervals)):
+            last = result[-1]
+            if last[1] >= intervals[i][0]:
+                result[-1] = [last[0], max(last[1], intervals[i][1])]
+            else:
+                result.append(intervals[i])
+        return result
+```
 
 Go：