Update 9.md

jackzhenguo · web-flow · commit 2516dc4cd478 · 2021-10-03T20:11:28.000+08:00
diff --git a/md/9.md b/md/9.md
@@ -17,6 +17,13 @@ In [1]: float('3')
 Out[1]: 3.0
 ```
 
+```python
+import sys
+
+In[4]: sys.float_info.max                                                      
+Out[4]: 1.7976931348623157e+308
+```
+
 正无穷大、负无穷大
 ```python
 float('inf') # 正无穷大
