Cutelyst a Qt/C++ Web Framework just got a new version. This time bringing back proper async support.

Perl Catalyst Framework was conceived as a sync/blocking framework, due that the Mojolicious framework was created, NodeJS and a few other web frameworks have pushed the async programming to the web. Performance wise being async doesn’t mean you get faster response times, rather the opposite, the need to unroll stack and make extra calls makes a CPU bound application slower.

But depending on the problem to solve it allows you to serve more users at the same time, using the same CPU cores. A typical modern application might receive a request from a Phone App then do a REST API call to an external API which might take 2ms or 200ms for the reply. While waiting for the response, typical sync/blocking applications can’t process more requests, or have to spawn more threads increasing RAM consumption and leveraging concurrency to the OS scheduler. On an Async web application, you can process another request while you wait for the previous request, thus possibly making the first request reply to be sent back to the user at a later time than if there was a dedicated process just waiting for his reply.

So, both ways have pros and cons and IMHO I’d like to support them both. When I started Cutelyst I thought that if I ever need async I could have a local QEventLoop to wait for the reply and would be able to deal with async requests, not recently I found out that supporting QEventLoop was causing stack overflow due it being used in pipelined scenarios, after that I removed it’s usage and performance improved in PlainText tests of TechEmpower, so I advised against using it and marked Cutelyst as not async.

• Converting Decimals to Roman Numerals with Bash

  My last few articles have given me a chance to relive my undergraduate computer science degree and code a Roman numeral to decimal converter. It's quite handy when you're watching old movies (when was MCMLVII anyway?), and the basic coding algorithm was reasonably straightforward. (See Dave's "Roman Numerals and Bash" and "More Roman Numerals and Bash".)

  The trick with Roman numerals, however, is that it's what's known as a subtractive notation. In other words, it's not a position → value or even symbol → value notation, but a sort of hybrid. MM = 2000, and C = 100, but MMC and MCM are quite different: the former is 2100, and the latter is 1000 + (–100 + 1000) = 1900.

  This means that the conversion isn't quite as simple as a mapping table, which makes it a good homework assignment for young comp-sci students!

• Creating a containerized Python/Flask development environment with Red Hat CodeReady Workspaces

  Red Hat CodeReady Workspaces provide developers with containerized development environments hosted on OpenShift/Kubernetes. DevOps teams can now use a hosted development environment that’s pre-built for their chosen stack and customized for their project.

  CodeReady Workspaces can help you rapidly onboard developers for your project as everything they need to develop is running in a containized workspace. In this post, we’re going to use CodeReady Workspaces to get up and running quickly with an existing open source project, Peak. Peak is a multi-container Kubernetes application for performance testing web services, and it allows you to create distributed performance tests using the Kubernetes Batch API for test orchestration. We’ll make some modifications to Peak’s Flask front end, a stateless web interface that interacts with a Falcon RESTful API to return data about performance tests. You won’t need the complete Peak application deployed, though if you like, you can find steps to deploy it to OpenShift here.

• How to Run Your Python Scripts

  One of the most important skills you need to build as a Python developer is to be able to run Python scripts and code. This is going to be the only way for you to know if your code works as you planned. It’s even the only way of knowing if your code works at all!

  This step-by-step tutorial will guide you through a series of ways to run Python scripts, depending on your environment, platform, needs, and skills as a programmer.

• Mike Driscoll: PyDev of the Week: Maria McKinley

  This week we welcome Maria McKinley (@twiteness) as our PyDev of the Week. Maria is a Senior Software Engineer at the Walt Disney Company and will be a speaker at PyCascades 2019. She is also teaching the Python Certificate Program at the University of Washington Continuing Education. Let’s spend a few moments getting to know her better.

• How To Program A Really Cheap Microcontroller

  There are rumors of a cheap chip that does USB natively, has an Open Source toolchain, and costs a quarter. These aren’t rumors: you can buy the CH552 microcontroller right now. Surprisingly, there aren’t many people picking up this cheap chip for their next project. If there’s no original projects using this chip, no one is going to use this chip. Catch 22, and all that.

  Like a generous god, [Aaron Christophel] has got your back with a working example of programming this cheap chip, and doing something useful with it. It blinks LEDs, it writes to an I2C display, and it does everything you would want from a microcontroller that costs a few dimes.

  The CH552, and its friends the small CH551 all the way up to the CH559, contain an 8051 core, somewhere around 16 kB of flash, the high-end chips have a USB controller, there’s SPI, PWM, I2C, and it costs pennies. Unlike so many other chips out there, you can find SDKs and toolchains. You can program the chip over USB. Clearly, we’re looking at something really cool if someone writes an Arduino wrapper for it. We’re not there yet, but we’re close.

• Chinese Tech Giant Baidu Launches Blockchain OS to Support DApp Development

  Chinese search engine and web services company Baidu has launched its Baidu Blockchain Engine (BBE), an operating system designed to facilitate decentralized application (DApp) development. The news was officially announced by Baidu’s cloud computing unit, Baidu Cloud, on Feb. 14.
  Baidu Cloud states that it considers an open source, commercialized platform to be “the only way to build a blockchain operating system.” BBE has reportedly been built on the basis of Baidu’s “ABC” technology strategy — artificial intelligence (AI), big data and cloud computing —  and aims to make DApp development “as simple as creating a mobile app.”

• How is the Eclipse Foundation Specification Process (EFSP) different from the Java Community Process (JCP)?

  As most of you are aware, Oracle has contributed the Java EE specification to the Eclipse Foundation. The enterprise Java community decided to rename the Java EE specification to Jakarta EE. Part of this huge transition to open source is changing the specification process. The famous Java Community Process (JCP) is going to be replaced by the Eclipse Foundation Specification Process (EFSP), which will be better suited for vendor neutrality, transparency, and all other attributes associated with open source. So what exactly is the difference?

  To learn more about the new process, please refer to the EFSP v1.0, and Wayne Beaton’s article in this newsletter.

• How To Build A Successful Developer Community

  As a community starter, the first question one should ask themselves is why developers want to join the community: is it because they are going to learn new skills or make their work easier?

  What is the impetus for building the community by asking questions like, whether the community is built around an open-source project? Are the developer tools available? Is there a platform with an API? Is it like a partner ecosystem? Or is it just selling a product?

• Ember.js video documentary released

  Besides being an interesting piece of content for developers and open-source enthusiasts around the world, the documentary also addresses the human element of open-source software and the power of community.

  The documentary starts off with Tom Dale telling the story about how in the early days of creating web apps using Javascript, people where telling them, "please stop using Javascript", and "you guys are abusing the system" - but they had to stick with the vision and see it through and today, everyone uses Javascript to create web applications.

• Why 2019 Will Be the Year for Shift-Left Mainframe Testing

  While 2018 was the year for planning and implementing shift-left methodologies in testing, mainframe and server testers were, for the most part, left behind. These legacy infrastructure experts were tied down to old-school testing tools. Mainframes kept functioning, but tools and testing practices often became bottlenecks, preventing performance testing teams from testing more quickly mid-cycle and pre-release.

• Ubisoft's Clever-Commit AI will sniff out bugs in Firefox

  GAMES DO ENCOURAGE VIOLENCE, but against bugs in the case Ubisoft which has partnered with Mozilla to build out an artificial intelligence (AI) system that sniffs out code gremlins.

  Dubbed Clever-Commit, the AI will act as a form of coding assistant that learns from a developer's base bug and regression data to predict and flag potential new bugs that might be added as new code is slapped onto the codebase.

  The system, which is already being used internally by Ubisoft, will be adopted by Mozilla to review Firefox code and spot dodgy bits, with the goal of making the browser more stable for its users. But if the systems works well, Mozilla has plans to stick it further into Firefox.

• Ubisoft and Mozilla team up to develop Clever-Commit, an AI coding assistant

  Game developer Ubisoft today announced that it has partnered with Mozilla to develop Clever-Commit, an AI-based coding assistant that learns from your code base’s bug and regression data to analyze and flag potential new bugs as new code is committed. Ubisoft already uses this tool internally and Mozilla  says that it will deploy it to spot bugs in its Firefox code.

• Programming languages: Python rides high but Groovy is cool again with developers

  Groovy, which came to life in 2007, hasn't been a top-20 language in Tiobe's index since 2016 but in the February listing it is now at 19th place, up from 49th last year. 

  Groovy hit its stride as a language for writing scripts for popular continuous-integration tool Jenkins, but it's also been buoyed by the Gradle open-source build-automation system. According to Tiobe, these days more 'glue' software is being written in Groovy. 

• The Deep Learning Framework Backed By Facebook Is Getting Industry's Attention

  When it comes to deep learning frameworks, TensorFlow is one of the most preferred toolkits.

• Inside the AI developer’s toolbox

• Guide To Web Scraping With Python Libraries Selenium & Beautiful Soup

• Speeding up basic object operations in Cython

• Python’s str.isdigit vs. str.isnumeric

• Test and Code: 65: one assert per test

• Setting up Tor hidden service

• How to install WildFly (JBoss) on Ubuntu 18.04

• Oracle Linux Installation on Virtualbox: Step By Step

• How to download Oracle Linux to install on VirtualBox

• How to Change User Password in Ubuntu [Beginner’s Tutorial]

• Introduction to Linux IO, Standard Streams, and Redirection.

• How to install Teamviewer 14 on Ubuntu 18.04

• Install Android 8.1 Oreo on Linux To Run Apps & Games

• Aligning the first line of a triple-quoted string in Python

• Continue with the boy boundary detection mechanism

  In the previous article, we have successfully made the boy climbing up the ladder but the boy will continue climbing even though there is no more ladder for him to climb. In this article, we will solve the previous problem by introducing the following rules. When the boy is climbing the ladder he can only move in either the upward or the downward direction but not side-way.

• PyBites: PyBites Twitter Digest - Issue 01, 2019