• Why use interpolated strings instead string.format


    If you know why you want to use an interpolated string, only those who have stepped on the pit can understand it. If you have ever used it string.format There are more than 5 placeholders. I think you can resonate with the pain. 1: Painful experience First of all, we have written a piece of […]

  • How to write simple and beautiful Python code


    By aniruddha BhandariCompile | VKSource | analytics vidhya summary Python style tutorial will enable you to write neat and beautiful Python code Learn about the different Python conventions and other nuances of Python Programming in this style tutorial introduce Have you ever encountered a poorly written Python code? I know a lot of you will […]

  • Mind mapping to learn the basics of JavaScript


    Learn the basics of JavaScript through mind mapping. Mind map includes the knowledge of variables, arrays, operators, function basis, string function, basic DOM operation, process statement and regular expression. For the original picture, click hereOriginal mind map variable array operator Function basis String function Basic DOM operations Flow statement regular expression

  • Learning go language 1 – basic grammar


    1、 The first go program Recently, I started to learn go language when I had nothing to do. In recent years, go language is very popular, supported by docker and kubernetes. It has become the mainstream programming language in the field of cloud computing, and has a tendency to encroach on some fields such as […]

  • Javascript: new features in ECMAScript 2020


    Interested can add wechat group If you can leave a message, you can notice the official account of WeChat’s public code, life code, life code, reply to the group, add me WeChat, pull you into the group, and say three important things. JavaScript is about to introduce exciting new features! Even if the final approval […]

  • Python learning notes: data type — number type


    Number type Numerical type, which is usually used to store values, is the most commonly used variable type;The numeric types in Python include the following types:Integer、Long integer、Boolean、Double-precision floating、Complex number。 IntegerPS novice note: many people in the process of learning Python will encounter a variety of vexed questions, no one answers easy to give up. For […]

  • Become a contributor Series in ten minutes | add optimization rules for cascades planner


    Author: Cui Yiding Up to now, “become a contributor series” has launched a series of activities such as “support ast restore to SQL”, “add build in function for tikv”, “vectorization expression”, etc.Taking advantage of the opportunity of tidb to optimize the database, we can take advantage of this opportunity to optimize the database. As we […]

  • It is very suitable for Xiaobai’s Python learning route


    Series articles: It is very suitable for Xiaobai’s Python learning route Self taught Python by Xiaobai (1) Python tutorial Xiaobai self taught python (2) construction of Python development environment Xiaobai taught himself python (3) basic syntax of Python Self taught Python by Xiaobai (4) Python data type Self taught Python by Xiaobai (5) Python operator […]

  • Flink — running architecture


    Task submission process Flink submits the task, and the client uploads Flink jar package and configuration to HDFS Then submit the task to the Yan ResourceManager The ResourceManager allocates the container resources and notifies the corresponding nodemanager to start the applicationmaster. After the applicationmaster starts, it loads Flink jar package and configuration to build the […]

  • Shell script


    Shell terminal interpreter There are two working modes of shell script command: interactive and batch processing. Interactive: each command entered by the user is executed immediately Batch: the user writes a complete shell script, and the shell will execute the commands in the script at one time Echo $shell ා using bash as the command […]

  • Unveiling tidb new optimizer: analysis of cascade planner principle


    Author: Mingcong Han In “ten minutes as a contributor series | adding optimization rules for cascades planner”, we briefly introduced the background knowledge of cascades. This paper will introduce the framework and principle of cascades planner, a new optimizer of tidb. Brief introduction of tidb current optimizer The function of query optimizer in relational database […]

  • Spring 5 Chinese parsing core chapter – the spice expression of IOC container


    Spring expression language (spel) is a very powerful expression language. It supports query at run time and manipulation of object graph manually. The language syntax is similar to El, but provides additional features, most notably method calls and basic string template functionality. There are several other Java expression languagesOGNL、MVELandJBoss ELYes, but the spring expression language […]