Update 0151.翻转字符串里的单词.md

增加python解法：使用双指针法移除空格

problems/0151.翻转字符串里的单词.md

@@ -516,6 +516,48 @@ class Solution:
         return s[:ps] + s[ps:][::-1] # Must do the last step, because the last word is omit though the pointers are on the correct positions,
 ```
 
+```python
+class Solution: # 使用双指针法移除空格
+    def reverseWords(self, s: str) -> str:
+        
+        def removeextraspace(s):
+            start = 0; end = len(s)-1
+            while s[start]==' ':
+                start+=1
+            while s[end]==' ':
+                end-=1
+            news = list(s[start:end+1])
+            slow = fast = 0
+            while fast<len(news):
+                while fast>0 and news[fast]==news[fast-1]==' ':
+                    fast+=1
+                news[slow]=news[fast]
+                slow+=1; fast+=1
+            #return "".join(news[:slow])
+            return news[:slow]
+
+        def reversestr(s):
+            left,right = 0,len(s)-1
+            news = list(s)
+            while left<right:
+                news[left],news[right] = news[right],news[left]
+                left+=1; right-=1
+            #return "".join(news)
+            return news
+
+        news = removeextraspace(s)
+        news.append(' ')
+        fast=slow=0
+        #print(news)
+        while fast<len(news):
+            while news[fast]!=' ':
+                fast+=1
+            news[slow:fast] = reversestr(news[slow:fast])
+        #    print(news[slow:fast])
+            fast=slow=fast+1
+        news2 = reversestr(news[:-1])
+        return ''.join(news2)
+```
 Go：
 
 ```go