save project

my_search.py

@@ -11,15 +11,13 @@ def binary_search(alist,num):
     high=len(alist)-1
     while low<=high:
         mid=(low+high)//2
-        guess=num_list[mid]
+        guess=alist[mid]
         if guess == num:
-            print("找到了")
-            break
+            return mid
         elif guess < num:
             low = mid + 1
         else:
-                high = mid-1
-            if low>high:
-                print("该数不存在")
-                break
-binary_search(alist,num )
\ No newline at end of file
+            high = mid-1
+        if low>high:
+            return None
+print(binary_search(alist,num ))
\ No newline at end of file