Update 001._two_sum.md

Author: 0xkookoo

docs/Leetcode_Solutions/Python/001._two_sum.md

@@ -7,15 +7,20 @@
 > 原题连接
 
 * https://leetcode.com/problems/two-sum
-* https://leetcode-cn.com/problems/two-sum/description
 
 > 内容描述
 
 ```
-给定 nums = [2, 7, 11, 15], target = 9
+Given an array of integers, return indices of the two numbers such that they add up to a specific target.
 
-因为 nums[0] + nums[1] = 2 + 7 = 9
-所以返回 [0, 1]
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+Example:
+
+Given nums = [2, 7, 11, 15], target = 9,
+
+Because nums[0] + nums[1] = 2 + 7 = 9,
+return [0, 1].
 ```
 
 ## 解题方案