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  Lock   It's like a synchronization block, java.util.concurrent.locks.Lock Is the thread synchronization mechanism. However, locks are more flexible and complex than synchronous blocks. Because lock is an interface, you need to use one of its implementations to use lock in your application. ReentrantLock is one such implementation of ...

subject 140. Word Split II Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, add spaces to the string to construct a sentence so that all words in the sentence are in the dictionary.Return all these possible sentences. Explain: Words in the dictionary can be reused when separating. You can assume that t ...

First question: use the requests library to visit Baidu homepage 20 times, and return the length of his text and content attributes.   1 # -*- coding: utf-8 -*- 2 """ 3 Created on Tue May 19 10:12:16 2020 4 5 @author: 49594 6 """ 7 8 import requests 9 url = "https://www.baidu.com/" 10 for i in range(20): 11 try: 12 rest ...

1, Swagger 1. What is Swagger? Swagger is a standardized and complete framework for generating, describing, invoking, and visualizing Restful style Web services.Simple understanding: it is a REST API document generation tool, which can generate online interface documents and facilitate interface testing. 2. Why Swagger? When front-end and back- ...

Link: https://www.jianshu.com/p/b8595aee06ac   CascadeType Summary Cascade refers to cascade operation, which is annotated in hibernate configuration @OneToOne，@OneToMany，@ManyToMany , @ ManyToOne properties Cascading is often used when writing triggers. The function of triggers is to ensure that the data in the associ ...

There are at least two types of errors in Python: syntax errors and exceptions. syntax error Syntax errors are also called parsing errors: >>> while True print('Hello world') File "<stdin>", line 1 while True print('Hello world') ^ SyntaxError: invalid syntax The parser indicates the error line ...

Replica set introduction What is a replica set -MongoDB replication is the process of synchronizing data on multiple servers. -Replication provides redundant backup of data and stores copies of data on multiple servers, improving data availability, And can ensure the security of data. -Replication also allows you to recover data from hardwa ...

YModem transmission mode: YModem, YModem-1K, YModem-g. In YModem-1k, the standard 128 byte transmission is replaced by 124 byte information fast transmission, and CRC teaching and research is used to ensure the accuracy of data transmission. YModem-g cancels the CRC check code of the data, and after sending a data block information, ...

Suppose you have installed bs4 requests This novel is chosen at will, so you don't have to worry too much Python 3 implementation. There are too many crawlers using Python 2 on the Internet, but there are still few crawlers using Python 3 The link is https://www.qu.la/book/12763/10664294.html Get the title of the article (find the exact htm ...

abstract stay Last article In, we talked about how to implement an Http server in Golang.But in the end, we can find that although DefaultServeMux can do routing distribution, its function is also imperfect. Routing distribution by DefaultServeMux is not a RESTful style API, and we cannot define the method required for requests or add query p ...