When running “pip uninstall ppp” to remove a Python pip package, unlike “apt-get remove uuu”, it seems it removes the package only without its useless depending packages, which will leave unused files there. How to improve it?

Every Java programmer knows the short answer(and the easiest one) is to create a class with multiple properties each of which is one value that you want to return in the method, and then you return an instance of this class from the method. But in many cases the returned values is just used one time, in such scenarios creating a class is too heavy and unnecessary. In Python, it’s very elegant to return a tuple in such scenarios. But in Java, what is the most elegant way to do it?

A table in MySQL database which saves the “user_count/shop_user_count” for specific place(“mall_id/floor_id”) and time(“dt”). The table structure is listed below.

Today after running “sudo apt-get update & sudo apt-get dist-upgrade”, the “ca-certificates” package is updated with the following output.

From here. The key is:

1. use pipe;

2. get the PID by using the “cut” command on the output of the “jps/ps” command and send the PID to the “kill” command.

The requirement is to update the origin SSH URL to HTTPS URL of a given git repo. Please read the following commands to get the details. From here.

From here and here.

“snap” is a Linux package system which aims to “package any app for every Linux desktop, server, cloud or device, and deliver updates directly”.

This post describes how to add “mind map” support in Octopress. The “mind map” content is in “markdown” format as part of an Octopress post, and rendered by the “KityMinder“ JavaScript library.

Promise is a mechanism for JavaScript to avoid the “callback hell” problem in asynchronous operations.

This is an example how to use Spring AOP.