让Python代码再次健壮
用户会给你填写奇奇怪怪的东西，你想好怎么应对了吗？今天在刷leetcode的pandas，2885. Rename Columns，有感而发。 直接看题目吧，其实很简单，但是我现在会想，万一有的测试样例里面，Column Name不是这四个，或者顺序错了怎么办。偷懒可以直接令columns = [,,,,,,]，但是如果顺序不对，缺少或者更多，程序都会报错。 DataFrame s...
Daniel Cheung's Blog | Data Science
Basic Literacy for Outlook Users
Except the inbox, he must check his junk box every day.
什么是杠杆ETF
杠杆ETF，英文Leveraged ETF，这是一种更为安全的杠杆投资方式。杠杆ETF相当于在原始投资标的的基础上添加了杠杆，其每日涨跌幅是追踪标的的杠杆倍数。 我们投资纳斯达克指数可以通过纳斯达克ETF（QQQ），当我们看多的时候，为了增加收益，可以买入两倍做多纳斯达克ETF（QLD）、三倍做多纳斯达克（TQQQ）。QLD每日涨幅是QQQ的两倍。同样的，看空的时候也可以买入做空是纳斯达克...
confuse about HK and SG railway systems
People who have once been to both Hong Kong and Singapore must be confused by how to distinguish MTR and MRT. The only difference is in the word order, and it is easy to mix up without long-term st...
Daniel Dreams Big | He reopen his blog, and this is a BRAND NEW blog!!!
Previously, I use blog system provided by third-party companies, that brings a log of restrictions. Platforms like CSDN also seem not friendly if I wish to publish any high-quality content, as blog...
分享一个python：合并pdf和图片转pdf的脚本
这是一个我用chatgpt生成的代码，并做了一些修改。 import os from PIL import Image from PyPDF2 import PdfMerger def convert_jpg_to_pdf(jpg_path, pdf_path): image = Image.open(jpg_path) image = image.convert('RG...
Invest indicators: take care of your holdings and avoid buying asset unwisely
When it comes to building a strong investment portfolio, selecting assets based on solid financial indicators is crucial. Among the most important metrics are Return on Equity (ROE), Price-to-Earni...
What is the difference between hundred digit and hundredth digit?
Give an example for this problem. w=26.956 Quantity A: The digit in the hundredths place of w Quantity B: The digit in the hundreds place of 4w The terms “hundreds place” and “hundredth...
Python与环境变量
本文联合创作：@Hanhan666666 & @sky96111 环境相关 python多版本共存 安装多个版本的python，需要安装在不同的目录下，全部添加到环境变量。where python和where pip操作会告诉你目前环境变量中包含哪些python。使用诸如vscode、pycharm的IDE可以很方便的指定指定版本的python，创建虚拟环境。 当然也有手动方...
使用VS code打开Jupyter报错Error loading webview
Windows操作系统 首先第一步是关掉code，这一步可以把所有文件都保存，然后进一步杀掉code，使用命令taskkill /im code.exe /f。删掉之后打开APPDATA文件夹，为了方便可以在文件浏览器的地址栏中输入%appdata%敲回车。进入code文件夹，删掉以下文件夹 Cache, CachedData, CachedExtensions, CachedExten...