Add new article for python.

Author: binarywizard

_drafts/python-tricks.md

@@ -0,0 +1,10 @@
+# Python 特性
+
+## 断言
+
+```python
+def apply_discount(product, discount):
+    price = int(product['price'] * (1.0 - discount))
+    assert 0 <= price <= product['price']
+    return price
+```

_posts/2019-11-28-问题集锦.md

@@ -7,7 +7,7 @@ tags:
   - 面试
 ---
 
-# 问题汇总
+## 设计原理
 
 1. uuid 是否有重复？
    - 自动 id 生成策略