About copying the code on Leetcode directly into your own environment

Example code (regardless of the pros and cons of the code):

Note: I use an online platform compiler

Problem1

• NameError：name ‘List’ is not defined
  
• Solution: Add the following code:

from typing import List

Problem2

• TypeError: threeSumClosest() missing 1 required positional argument: ‘target’
  
• Solution:

S = Solution()

• Analysis: In Python, the class should be instantiated first, and then the class should be applied. Note that the instantiation process should be parenthesized.