Programmer Group

Use domain events to capture something that happens in the domain. Domain-driven practitioners find that they can better understand the problem domain by understanding more events that occur in the problem domain. These events are domain events, which are mainly acquired in the process of knowledge extraction with domain experts. Domain events ...

BFs In fact, breadth-first search is hierarchical traversal, and the program is implemented by queue. Algorithmic thought Beginning with the root, the solution space tree of the problem is often searched by BF or in the way of minimum cost (i.e. maximum benefit) priority. Firstly, the root node is added to the live node table, and then the root ...

The commands in this article are all real-time under the mongo shell. In real web projects, the corresponding implementations of these commands are encapsulated, so there is no need to be scared. Put on the official orthodox documents first English document The links below are all from the Chinese community. There are many ways for ...

Linux's command line provides many commands to kill a process.For example, you can pass a PID to kill a process; the pkill command uses a regular expression as input, so processes matching that pattern are killed. But there is also a command called killall, which by default matches the parameter name exactly and then kills the matching proce ...

Simply put, Numpy is used for matrix calculation, while Pandas is based on Numpy, which enriches and simplifies Numpy's operation. Numpy Basic operation import numpy as np array = np.array([[1, 2, 3], [2, 3, 4]], dtype=np.int) #dtype is the element data type a = np.zeros((3, 4)) # Zero Matrix of 3 Rows and 4 ...

let and const In JavaScript, we used to use key var to define variables. After ES6, we added two keywords to define variables, let and const. For variables, variables defined by var in ES5 will be raised to all functions and statements in scope, while variables defined by let in ES6 will not. Variables declared by let will est ...

Pool Area is a core container in Netty memory pool. Its main function is to manage a series of Pool Chunks and Pool Subpages created, and to delegate the final application action to these two sub-containers according to the different memory size of the application. This paper first introduces the overall structure of PoolArena, then introduces ...

The python3 crawler encountered a backcrawl When you excitedly open a web page and find that the resources inside are great, you can download them in batches. Then thank you for writing a crawler download. As a result, after an operation, you find that the website has anti-crawling measures, which is embarrassing. In the next few articles, we w ...

Definition of graph A graph G = (V,E) consists of a vertex set V and an edge set E. Each edge is a pair of points (v,w), where v,w < V, sometimes referred to as an arc. If the pairs of points are ordered, the graph is called directed, and the directed graph is sometimes called digraph. Vertices V and W adjacent if and only ...

Slacker Introduction These two points are enough to show that this article does not want to have any high-end atmospheric technology content, I tell you, it's all water. There can't be any prime number, elliptic curve cryptography, Diffy-Herman or anything, there can't be. First of all, I don't understand it. Second, you don't understand it a ...