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Legacy Languages still Pretty Hard to Beat

Reading time3 min
Views2K
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Evolution and development have always been the integral parts of every sector you come across. Same is the case with programming languages. Numerous up gradations and invention of entirely new languages have divided the world of programming into legacy and modern. But no matter what, legacy programming still makes the foundation of many software, web applications and AI based techniques.
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Developing and deploying Python for secured environments with Kushal Das

Reading time7 min
Views1.5K
Here is the translated Russian version of this interview.

The company of speakers at Moscow Python Conf++ 2020 is great, and it's not a good luck but thorough Program Committee's work. But who cares about achievements, it's much more interesting what the speaker thinks about our own questions. Conferences suits good to find it out, get insider information or advice from an experienced developer. But I got an advantage of being in Program Committee so I already asked our speaker Kushal Das some questions.

A unique feature of Kushal's speeches is that he often unveils «secret» ways to break Python code and then shows how to write code so that the NSA can't hack it. At our conference Kushal will tell you how to safely develop and deploy Python code. Of course I asked him about security.

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buildroot — my own experience with multi-platform distro creation

Reading time5 min
Views6.1K

Introduction


In my previous article (Monitor linux) I wrote, what is this distro and how it works. Now i will write how to do it. It's may be interesting for everyone, who want to study buildroot.


Target goals


The result we get from article is the following:


  • Firmware (non-volatile image with restorable config)
  • Easy management via web-interface
  • Cross-platform (qemu x86_64, arm-based SBC like rasberry 4, beagle bone black and asus tinker board)
  • Support without extra effort
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Are my open-source libraries vulnerable? (2 min reading to make your life more secure)

Reading time2 min
Views2.6K

The explosion of open source and issues related to it


The amount of open source or other third party code used in a software project is estimated as 60-90% of a codebase. Components, such as libraries, frameworks, and other software modules, almost always run with full privileges. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications using components with known vulnerabilities may undermine application defences and enable a range of possible attacks and impacts.



Conclusion: even if you perform constant security code reviews, you still might be vulnerable because of third-party components.

Some have tried to do this manually, but the sheer amount of work and data is growing and is time consuming, difficult, and error prone to manage. It would require several full time employees and skilled security analysts to constantly monitor all sources to stay on top.
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Free API Moscow Stock Exchange (MOEX) in Google Sheets

Reading time2 min
Views10K
Last year the number of private investors at Moscow Stock Exchange (MOEX) has doubled and reached 3.86 million: about 1.9 million people have opened accounts at MOEX in 2019. The Saint Petersburg Stock Exchange which specializes in trading of foreign company shares has seen its accounts increase three times from 910,000 to 3,06 million over the past year.



This means that almost 2 million newbies without any actual trading experience and lacking any specialized software for trading/position analysis have entered the market.
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Developing a symbolic-expression library with C#. Differentiation, simplification, equation solving and many more

Reading time15 min
Views8.2K
Hello!

[UPD from 12.06.2021: if you're looking for a symbolic algebra library, AngouriMath is actively developed. It's on Github and has a website. Discord for questions]

Why does programming a calculator seem to be a task, which every beginner undertakes? History might have the answer — computers were created for this exact purpose. Unlike the beginners, we will develop a smart calculator, which, although won't reach the complexity of SymPy, will be able to perform such algebraic operations as differentiation, simplification, and equations solving, will have built-in latex support, and have implemented features such as compilation to speed up the computations.

What are the articles about?
It will superficially tell about assembling an expression, parsing from a string, variable substitution, analytic derivative, equation numerical solving, and definite integration, rendering to LaTeX format, complex numbers, compiling functions, simplifying, expanding brackets, and blah blah blah.
For those who urgently need to clone something, repository link.

Let's do it!
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Apache Hadoop Code Quality: Production VS Test

Reading time11 min
Views702

Рисунок 1

In order to get high quality production code, it's not enough just to ensure maximum coverage with tests. No doubts, great results require the main project code and tests to work efficiently together. Therefore, tests have to be paid as much attention as the main code. A decent test is a key success factor, as it will catch regression in production. Let's take a look at PVS-Studio static analyzer warnings to see the importance of the fact that errors in tests are no worse than the ones in production. Today's focus: Apache Hadoop.
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MVCC in PostgreSQL-4. Snapshots

Reading time9 min
Views6.7K
After having discussed isolation problems and having made a digression regarding the low-level data structure, last time we explored row versions and observed how different operations changed tuple header fields.

Now we will look at how consistent data snapshots are obtained from tuples.

What is a data snapshot?


Data pages can physically contain several versions of the same row. But each transaction must see only one (or none) version of each row, so that all of them make up a consistent picture of the data (in the sense of ACID) as of a certain point in time.

Isolation in PosgreSQL is based on snapshots: each transaction works with its own data snapshot, which «contains» data that were committed before the moment the snapshot was created and does not «contain» data that were not committed by that moment yet. We've already seen that although the resulting isolation appears stricter than required by the standard, it still has anomalies.
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How to cook RTSP on your website in 2020, or why the boars will not have a chance to run away

Reading time8 min
Views45K


RTSP is a simple signaling protocol which they cannot replace with anything for many years already, and it has to be admitted that they don't try really hard.


For example, we have an IP camera that supports RTSP. Anyone who has ever tested the traffic with a Sharkwire cable will tell you that first there comes DESCRIBE, then PLAY, and then the traffic begins to pour directly via RTP or wrapped in the TCP channel for instance.

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Cracking Reduce Concept In Just 10 Minutes

Reading time3 min
Views1.4K


Being a developer, I love to code especially in JavaScript. As per my experience, using reduce function is one of the toughest tasks in JS. Let me first elaborate on the Reduce concept!

In Wikipedia, it has many names viz.

Reduce
Fold
Accumulate
Aggregate
Compress

It is a function that folds a list into any data type. It's all about breaking a structure down into a single value. It's like folding a box! With reduce, you can turn an array [1,2,3,4,5] into the number 15 by adding them all up.
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Cloud-based WebRTC streaming on DigitalOcean

Reading time5 min
Views4.5K


Popular cloud hosting DigitalOcean has recently launched its new marketplace selling preconfigured images that can help to quickly deploy an application server. It’s much like AWS, but DO is for those already using this provider’s services. Let’s see how to deploy a simple server for WebRTC streaming with a DO account for a $10/month fee based on Flashphoner WebCallServer and how such a server can be of use.

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Now is the time to make a fresh new Windows Terminal profiles.json

Reading time3 min
Views7.7K
I've been talking about it for months, but in case you haven't heard, there's a new Windows Terminal in town. You can download it and start using it now from the Windows Store. It's free and open source.

At the time of this writing, Windows Terminal is around version 0.5. It's not officially released as a 1.0 so things are changing all the time.

Here's your todo - Have you installed the Windows Terminal before? Have you customize your profile.json file? If so, I want you to DELETE your profiles.json!

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The science behind how our brains work best, and how technology and our environment can help

Reading time5 min
Views1.7K


You’re utterly focused. You’ve lost track of time. Nothing else in the world exists. You’re living in the moment.

While this might sound like meditation, it’s a description that can also be applied to the state of flow – the feeling of being so engaged by your work, that you lose yourself to it completely, while massively increasing your productivity in the process.

It’s the holy grail that we all strive for, whether it’s a hobby we’re passionate about, or a project at work. Achieving our best and utilising our maximum potential at all times, can however, be a struggle.
We had the pleasure of talking with Dr. Jack Lewis, a neuroscientist with a passion for exploring how our minds work, to see what motivates us to do our best work, and the important roles that workplace environments, culture, and technology can play.
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Machine Learning for your flat hunt. Part 2

Reading time9 min
Views1.7K


Have you thought about the influence of the nearest metro to the price of your flat? 
What about several kindergartens around your apartment? Are you ready to plunge in the world of geo-spatial data?


The world provides so much information…



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What's new in ML.NET and Model Builder

Reading time2 min
Views1K
We are excited to announce updates to Model Builder and improvements in ML.NET. You can learn more in the «What’s new in ML.NET?.» session at .NET Conf.

ML.NET is an open-source and cross-platform machine learning framework (Windows, Linux, macOS) for .NET developers.

ML.NET offers Model Builder (a simple UI tool) and CLI to make it super easy to build custom ML Models using AutoML.

Using ML.NET, developers can leverage their existing tools and skillsets to develop and infuse custom AI into their applications by creating custom machine learning models for common scenarios like Sentiment Analysis, Recommendation, Image Classification and more!..

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Family tree inside Git

Reading time6 min
Views4.2K

Happy programmer's day! I wish you more bright commits, merged pull requests, less merge conflicts, and that your life branches remain relevant as long as possible. As a conceptual gift, I propose the implementation of a family tree by means of the Git version control system. Well… sounds like a plan!



For those who have immediately understood everything, I give links to the source code: GenealogyTreeInGit and family trees: mine and US presidents.


In addition, I implemented a simple social graph. It displays not only the degree of kinship, but also the status of relations between descendants, events such as wedding, divorce, childbirth, as well as contributions to the relations.

More about implementation, details, and pictures

How I prepared for and passed the Oracle Database SQL Certification (1Z0-071)

Reading time9 min
Views22K

Why did I write this article?


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When I was preparing for Java 8 OCA and OCP I found a lot of useful articles about subjects on Habr that helped me to choose the optimal path and save a considerable amount of time.


When I started preparing for OCA Oracle Database SQL (1Z0-071) I didn’t find any materials on Habr about this matter and found there to be limited information available on the Internet. Because of this I decided to write a complete guide in order to help others who are interested in this certification to help them save time and successfully pass what I consider to be a pretty hard exam.

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Escaping the Thicket of Tests: Building a Shortcut from a Fixture to an Assertion

Reading time15 min
Views1.2K


In this article, I would like to propose an alternative to the traditional test design style using functional programming concepts in Scala. This approach was inspired by many months of pain from maintaining dozens of failing tests and a burning desire to make them more straightforward and more comprehensible.


Even though the code is in Scala, the proposed ideas are appropriate for developers and QA engineers who use languages supporting functional programming. You can find a Github link with the full solution and an example at the end of the article.

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