Programmer Group

First, the definition of modularity. ① With file scope ② With communication rules: Rules for loading and exporting 2, CommonJS module specification 1. The module system in nodejs has file scope and communication rules. It uses the require method to load the module, and uses the exports interface object to export the members of the module. 2 ...

Actual combat of e-commerce offline warehouse project (Part 2) E-commerce analysis - core transactions 1, Business requirements Select indicators: order quantity, commodity quantity and payment amount, and analyze these indicators by sales region and commodity type. 2, Business database table structure 1. Relationship between databas ...

preface In blog Opencv Python practice (4) -- common OpenCV image processing technologies( ❤️ 10000 word long text, including a large number of examples ❤️)> As described in, you can apply CV2. Bilaterfilter () To reduce noise while retaining sharp edges. However, this filter will produce ladder effect and false edges in the filtered im ...

Usage scenario There will be more and more company based projects, and it is often necessary to extract a public class library for multiple projects, but how can this library be easily managed with git? We need to solve the following problems: How do I import the library library in a git project? The library library has been modified in oth ...

The implementation principle of AtomicLong is consistent with AtomicInteger, except that one is for long variables and the other is for int variables. How does the AtomicBoolean class update the boolean variable? The core method is compareandset method, and its source code is as follows: public final boolean compareAndSet(boolean expect, bool ...

Chapter 2: xml, http protocol, tomcat 1.XML 1.1 XML overview 1. What is xml: English Extensible MarkUp Language. Extensible markup language: markup in xml is extensible.xml version number 1.0, 1.1 xml usage: it is used to store data1. As the format of data transmission between systems2. As the configuration file of the project3. Save data with ...

Fundamentals of Java (19)—— 1, Thread safety (sync lock and monitor) 1. Primer -- thread unsafe For example, introduce a security lock: 10 stores, selling 1000 computers at the same time. The code is 10 threads competing for a resource (the code is as follows): This will cause a serious problem, that is, multiple threads will c ...

Earlier, we introduced the handshake of WebSocket: C # implements WebSocket server: (01) handshake After the handshake is completed, both the client and the server can send and receive messages. WebSocket messages are sent and received in frames. 0. WebSocket frame Frame type Op There are six common frame types: valuetypeexplain0x00Continua ...

Note: at present, there is no Chinese translation of the latest official documents of TypeScript on the Internet, so there is such a translation plan. Because I am also a beginner of TypeScript, I can't guarantee the 100% accuracy of translation. If there are errors, please point them out in the comment area;Translation content: the tentative t ...

I won't talk about the process of installing Python and Selenium. Let's go directly to the code below. The goal is to download all the documents (PDF format) of a certain issue of a journal on HowNet. Here with Educational research Take this journal as an example, Download all the documents in issue 5 of 2021. 1 download Chrome's Webdriver ...