Solution to “Python3.12pip network installation library file error, ssl module is unavailable”

Solution to “Python3.12pip network installation library file error, ssl module is unavailable” 1. Install the new version of openssl3.1.4 2. Install Python3.12.0 The Python version needs to match the openssl version. In versions after Python 3.7, the dependent openssl must be a version after 1.1.1 or 1.0.2, and the openssl1.0.2k installed in CentOS7 cannot meet […]

Thread status and thread safety issues

Article directory Thread status All states of the thread Thread state transition Multi-threading vs. Single-thread Efficiency Improvement Risks of Multithreading – Thread Safety Issues Case analyze reason Solution synchronized keyword – monitor lock Use the synchronized keyword Features of synchronized mutually exclusive reentrant Thread-safe classes in the Java standard library deadlock What is deadlock Three […]

Understanding Crontab in Linux With Examples

The crontab is used to automate all types of tasks on Linux systems. This is an especially important skill for aspiring system administrators to learn. It can be somewhat challenging to get started if you’re a beginner. The syntax is different than most other commands. For this reason, this lesson will include a little more […]

One Demo handles the front-end and back-end multi-part uploading of large files, resumed uploading at breakpoints, and instantaneous uploading.

1Foreword File uploading is very common in project development. Most projects will involve the uploading of pictures, audios, videos, and files. Usually a simple Form can upload small files, but when encountering large files, such as more than 1GB, or When the user’s network is relatively slow, simple file upload is not applicable. The user […]

LC-1334. The city with the fewest neighbors within the threshold distance (Floyd algorithm, memorized search ==> dynamic programming (0x3f))

1334. The city with the fewest neighbors within the threshold distance medium There are n cities, numbered from 0 to n-1. Give you an edge array edges, where edges[i] = [fromi, toi, weighti] represents fromi and toi code> A bidirectional weighted edge between two cities, the distance threshold is an integer distanceThreshold. Returns the city […]

[Data structure] Simulation implementation of stack and queue (implemented in two ways)

Foreword About the author: Come on, Xu Xing, currently a sophomore, currently learning C++, Data Structure, etc. Author’s homepage: Come on, Xu Xing’s homepage ?This article is included in: Re-recognizing the advanced column of C Code Warehouse: Rising Sun 1 Everyone is welcome to like Collect ? Follow! Learning objectives: This blog will learn about […]

Use the Stream stream to convert the obtained object List<Object>form data into Map<Grouping conditions, quantity statistics>form

For example, the current business needs to group the obtained data, and then use another method to process the data. The methods used are Collectors.groupingBy, Collectors.counting(), Collectors.reducing(). Then, take the following example as an example to collect the obtained lists and group the obtained data by gender, with gender as K and the number of […]

Instances of all methods in the list type (except sort) and explanations (called through help (list))

1. Overview After using help (list) and running it, you can see the following methods: append, clear, copy, count, extend, index, insert, pop, remove, reverse, a total of ten methods. Next, I will give examples one by one. explain. 2. Examples and explanations 1.append: Append object to the end of the list. (Append object to […]