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Programming Leftovers

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Development
  • Excellent Free Tutorials to Learn Tcl - LinuxLinks

    Tcl (Tool Command Language) is a dynamic programming/scripting language based on concepts of Lisp, C, and Unix shells. Here's our recommended free tutorials to learn Tcl.

  • ROC and Precision-Recall curves - How do they compare?

    Both curves offer two useful information: how to choose the positive class prediction threshold and what is the overall performance of the classification model. The former is determined by selecting the threshold which yield the best tradeoff, in adequation with the prediction task and operational needs. The latter is done by measuring the area under the curves which informs about how good the model is, because by measuring the area under the curves, one computes the overall probability that a sample from the negative class has a lower probability than a sample from the positive class.

    With scikit-learn, the values can be computed either by using the roc_auc attribute of the object returned by plot_roc_curve() or by calling roc_auc_score() directly for ROC curves and by using the average_precision attribute of the object returned by plot_precision_recall_curve() or by calling average_precision_score() directly for PR curves.

  • Write GIMP scripts to make image processing faster | Opensource.com

    Some time ago, I wanted to give a blackboard-style look to a typeset equation. I started playing around with the GNU Image Manipulation Program (GIMP) and was satisfied with the result. The problem was that I had to perform several actions on the image, I wanted to use this style again, and I did not want to repeat the steps for all the images. Besides, I was sure that I would forget them in no time.

  • Bash wait Command | Linuxize

    wait is a command that waits for the given jobs to complete and returns the exit status of the waited for command.

    Since the wait command affects the current shell execution environment, it is implemented as a built-in command in most shells.

    In this article, we’ll explore the Bash built-in wait command.

  • Santiago Zarate: Cron do not send me empty emails
  • Rust & the case of the disappearing stack frames | Inside Rust Blog

    Now that the FFI-unwind Project Group has merged an RFC specifying the "C unwind" ABI and removing some instances of undefined behavior in the "C" ABI, we are ready to establish new goals for the group.

    Our most important task, of course, is to implement the newly-specified behavior. This work has been undertaken by Katelyn Martin and can be followed here.

Programming Leftovers

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Development
  • An Introduction to Bash Brace Expansion

    The Borne Again Shell (BASH) has a lot of great features that it borrows from other shells and even from some programming languages. It was created in the late 1980s in a response to a lacking in the current available shells on Berkley Distributions (BSD), and the predecessor to Linux, GNU. BASH features numerous in-built features such as in-line scripting capabilities like brace expansion, which we are going to examine today.

  • Rakudo Weekly News: 2021.04 Grant Reporting
  • The Trouble with Reference Counting

    Perl uses a simple form of garbage collection (GC) called reference counting. Every variable created by a Perl program has a refcnt associated with it. If the program creates a reference to the variable, Perl increments its refcnt. Whenever Perl exits a block it reclaims any variables that belong to the block scope. If any are references, their referenced values’ refcnt are either decremented or they’re reclaimed as well if no other references to them remain.

  • Dustin J. Mitchell: The Horrors of Partial-Identity Encodings -- or -- URL Encoding Is Hard

    URL encoding is a pretty simple thing, and has been around forever. Yet, it is associated with a significant fraction of bugs in web frameworks, libraries, and applications. Why is that? Is there a larger lesson here?

  • Enrico Zini: nspawn-runner: support for image selection

    .gitlab-ci.yml supports 'image' to allow selecting in which environment the script gets run. The documentation says "Used to specify a Docker image to use for the job", but it's clearly a bug in the documentation, because we can do it with nspawn-runner, too.

    It turns out that most of the environment variables available to CI runs are also available to custom runner scripts. In this case, the value passed as image can be found as $CUSTOM_ENV_CI_JOB_IMAGE in the custom runner scripts environment.

  • Introduction to Making GraphQL APIs and Apps in Node.js – Linux Hint

    The communication and data transfer between the front end and backend of any application occurs through APIs (Application Programming Interface). There are many different types of APIs used to communicate between the front and back-end applications like RESTful API, SOAP API, GraphQL API, etc. The GraphQL API is a relatively new technology, and it is much faster than other types of APIs available. Fetching data from the database using GraphQL api is much faster than the REST API. While using GraphQL API, the client has control to fetch only the required data instead of getting all the details; that is why GraphQL API works faster than REST API.

  • Issue with phpMyAdmin and PHP: Warning in ./libraries/sql.lib.php#613 count(): Parameter must be an array or an object that implements Countable”

    Today, I had installed PHP 7.3 and phpMyAdmin on Ubuntu 18.04 LTS system. I am using MariaDB as database server running on the same instance. When I tried to access data in tables using phpMyAdmin got the following error message on screen.

  • C++ Access Specifiers – Linux Hint

    In C++, a class is a set of variables and functions that have been configured to work together. When the variables of the class are given values, an object is obtained. An object has the same variables and functions as a class, but this time, the variables have values. Many objects can be created from one class. One object differs from another object according to the different set of values assigned to the variables of the other object. Creating an object from a class is said to be instantiating the object. Even if two different objects have the same values for their variables, these objects are different entities, identified by different names in the program. The variables for an object and its corresponding class are called data members. The functions of an object and its corresponding class are called member functions. Data members and member functions are called members.

    The word access means to read or change the value of a variable, and it also means to use a function. C++ access specifiers are the words, “private,” “protected,” and “public.” They decide whether a member can access other members of its class, or if a function or operator outside the class and not belonging to the class can access any member of the class. They also decide whether a member of a derived (child) class can access a member of a parent class.

    Basic knowledge of C++ is required to understand this article and to test the code provided.

  • Compiling Code in Parallel using Make – Linux Hint

    Whoever you ask how to build software properly will come up with Make as one of the answers. On GNU/Linux systems, GNU Make [1] is the Open-Source version of the original Make that was released more than 40 years ago — in 1976. Make works with a Makefile — a structured plain text file with that name that can be best described as the construction manual for the software building process. The Makefile contains a number of labels (called targets) and the specific instructions needed to be executed to build each target.

    Simply speaking, Make is a build tool. It follows the recipe of tasks from the Makefile. It allows you to repeat the steps in an automated fashion rather than typing them in a terminal (and probably making mistakes while typing).

    Listing 1 shows an example Makefile with the two targets “e1” and “e2” as well as the two special targets “all” and “clean.” Running “make e1” executes the instructions for target “e1” and creates the empty file one. Running “make e2” does the same for target “e2” and creates the empty file two. The call of “make all” executes the instructions for target e1 first and e2 next. To remove the previously created files one and two, simply execute the call “make clean.”

  • Zeal – simple offline documentation browser

    Zeal is billed as a simple offline documentation browser. It offers easy access to a huge database of documentation, API manuals, and code snippets.

    The main purpose of the software is to enable you to have reference documentation at your fingertips. Let’s see how it fares.

NumPy (Python) Series

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Development
  • How to Use Python NumPy Array – Linux Hint

    Many libraries exist in Python to perform different types of tasks. NumPy is one of them. The full form of NumPy is Numerical Python, and it is mainly used for scientific computing. Multi-dimensional array objects can be defined by using this library that is called the Python NumPy array. Different types of functions exist in the NumPy library to create the array. NumPy array can be generated from the python list of numeric data, range of data, and random data. How NumPy array can be created and used to do different operations types have shown in this tutorial.

  • How to Use Python NumPy arange() Function – Linux Hint

    Many functions exist in the Python NumPy library to perform different types of numerical and scientific operations. Creating different types of arrays for various purposes is one of the practical uses of the NumPy library. Python has a built-in function named arange() to create a list of sequential numbers. arange() is one of the array creation functions of the NumPy library to create an array of numeric ranges. The uses of the NumPy arange() function have explained in this tutorial.

  • How to Use Python NumPy reshape() Function – Linux Hint

    NumPy library has many functions to work with the multi-dimensional array. reshape () function is one of them that is used to change the shape of any existing array without changing the data. The shape defines the total number of elements in each dimension. The array’s dimension can be added or removed, and the number of elements in each dimension can be modified by using the reshape() function. The one-dimensional array can be converted into a multi-dimensional array, but the multi-dimensional array can’t be converted into a one-dimensional array by this function. How to reshape() function works and its uses are explained in this tutorial.

  • How to Use Python NumPy zeros() and ones() Functions – Linux Hint

    NumPy library is one of the useful libraries of python that can be used to create arrays. zeros() and ones() are the NumPy library functions to create two different arrays. zeros() function is used to create an array based on the particular shape and type. All array elements are initialized to 0, which is created by the zeros() function. ones() function works like the zeros() function. But the elements of the array created by the ones() function are initialized to 1. The uses of both functions have shown in this tutorial by using multiple examples.

  • How to convert Python NumPy array to python list – Linux Hint

    Array object is used to store multiple values, and the list object is used in Python to do a similar task to an array object. NumPy array object is used to do different types of numerical operations in Python. The multi-dimensional array can be created by using this library. NumPy library has a built-in tolist() function to convert the NumPy array to the python list. This function does not take any argument and returns the python list. If the array is one-dimensional, then the function will return a simple python list. If the array is multi-dimensional, then the array will return the nested python list. If the array’s dimension is 0, then the function will return a python scalar variable instead of a list. How tolist() function can convert different types of NumPy array to python list is shown in this tutorial.

  • How to install NumPy python development environment on Ubuntu – Linux Hint

    Python is a modern programming language now for supporting a large number of libraries. Various types of tasks can be done by using these libraries. NumPy is one of the useful libraries of Python to perform scientific operations. This library can be used to create a multi-dimensional array of objects. Different types of mathematical tasks can be done quickly using this library, such as sorting the array, reshaping array, statistical operation, arithmetical operations, etc. It works faster because it is developed by using the C programming language.

  • Python Unittest Tutorial

    Unit testing is a testing method used in software engineering for individual units of any code. Users can put the individual tests to determine the status of the source and how much the code is suitable to be used. This way users can test the code quality.

    Testing is done once the process of development is complete. Users can also begin testing when the test script is to be verified based on the criteria of the testing. Developers are expected to write the manual types of the source code. Generally, manually writing unit testing codes is a hectic task but in Python, it is done using an in-built function called unittest.

Programming Leftovers

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Development
  • Period, Duration and Instant in Java

    Period, Duration and Instant are three different classes introduced since Java 8 to help us deal better with time.

  • Pyston 2.1 Is Blowing Past Python 3.8/3.9 Performance

    With this past week's release of Pyston 2.1 as an alternative Python interpreter I was curious to see how the performance compared to that of upstream Python... So here are some weekend benchmarks with a Ryzen 9 5900X system.

    On a Ryzen 9 5900X system running Ubuntu 20.10, I ran a few Python benchmarks using its stock Python 3.8.6 installation, Python 3.9.1 as the latest upstream and built from source in an optimized mode, and then the Pyston 2.1 x86_64 Linux binary. Pyston 2.x still is (sadly) binary-only for now.

  • gfldex: Chain calling

    When working with IO::Path we have to take platform dependent directory separator into account. To alleviate the problem .add was added. Surprisingly there is no candidate that takes a list. So we have to chain method calls as if we would use an inferior language.

  • A Beginner’s Guide to R Programming | EC-Council Blog

    R is a free software environment for statistical computing and graphics. It is used for complex analysis such as correlation, clustering, and data reduction. Learn everything about the fundamental programming concepts in R and more.

Programming Leftovers

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Development
  • How to test PHP code using PHPUnit - Anto ./ Online

    PHPUnit automatically executable tests that verify your application’s behavior. Thus – you can ensure that your changes don’t break existing functionality. This post will show you how to test your PHP code using PHPUnit.

  • Latency Numbers Every Team Should Know

    We design systems around the size of delays that are expected. You may have seen the popular table “latency numbers every programmer should know” which lists some delays that are significant in technology systems we build.

    Teams are systems too. Delays in operations that teams need to perform regularly are significant to their effectiveness. We should know what they are.

    Ssh to a server on the other side of the world and you will feel frustration; delay in the feedback loop from keypress to that character displayed on the screen.

    Here’s some important feedback loops for a team, with feasible delays. I’d consider these delays tolerable by a team doing their best work (in contexts I’ve worked in). Some teams can do better, lots do worse.

    [...]

    In recent times you may have experienced the challenge of having conversations over video links with significant delays. This is even harder when the delay is variable. It’s hard to avoid talking over each other.

    Similarly, it’s pretty bad if we know it’s going to take all day to deploy a change to production. But it’s so worse if we think we can do it in 10 minutes, when it actually ends up taking all day. Flaky deployment checks, environment problems, change conflicts create unpredictable delays.

    It’s hard to get anything done when we don’t know what to expect. Like trying to hold a video conversation with someone on a train that’s passing through the occasional tunnel.

  • How I programmed a virtual gift exchange

    Every year, my wife's book club has a book exchange during the holidays. Due to the need to maintain physical distance in 2020, I created an online gift exchange for them to use during a book club videoconference. Apparently, the virtual book exchange worked out (at least, I received kind compliments from the book club members), so I decided to share this simple little hack.

  • Dirk Eddelbuettel: prrd 0.0.4: More tweaks

    The key idea of prrd is simple, and described in some more detail on its webpage and its GitHub repo. Reverse dependency checks are an important part of package development that is easily done in a (serial) loop. But these checks are also generally embarassingly parallel as there is no or little interdependency between them (besides maybe shared build depedencies). See the (dated) screenshot (running six parallel workers, arranged in split byobu session).

    This release brings several smaller tweaks and improvements to the summary report that had accumulated in my use since the last release last April. We also updated the CI runners as one does these days.

  • vrurg: A New Release Of Cro::RPC::JSON

    I don’t usually announce regular releases of my modules. But not this time. I start this new year with the new v0.1 branch of Cro::RPC::JSON. Version 0.1.1 is currently available on CPAN (will likely be replaced with fez as soon as it is ready). The release is a result of so extensive changes in the module that I had to bump its :api version to 2.

  • gfldex: Anonymous slurpers

    I have a script where I’m only interested in the last two lines of its output.

Python Programming

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Development
  • How to Create a Database in MongoDB Using Python

    There’s no doubt that Python is a powerful—and popular—programming language capable of handling any project we throw its way. It is very flexible and can adjust to suit various development environments like penetration testing to web development and machine learning.
    When coupled to large applications such as those that require databases, Python adds more functionality and can be hard to work with, especially for beginners.

    Python knows this add provides us with better ways to add databases to our projects without compromising our workflow using a simple and intuitive NoSQL database. Using Python and a popular NoSQL database, MongoDB, development becomes more comfortable and, all in all, fun.

    This article will go over various MongoDB database concepts to give you a firm understanding of what it entails. After that, we will cover how to install MongoDB on Linux and show you how to use Python to interact with MongoDB.

  • Python Script to Monitor Network Connection

    The need to have our devices always connected to the internet is becoming more of a basic need than an added privilege.

    Having applications and devices that need to log, send, and receive data to the outside world is critical. Thus, having a tool that allows you to monitor when your network goes down can help you troubleshoot the network or stop the applications before sending a bunch of log errors.

    In today’s tutorial, we will build a simple network monitor that continually monitors your internet connectivity by sending ping requests to an external resource. The script we shall create shall also keep logs of when the internet is down and the duration of the downtime:

  • How to Build a Web Traffic Monitor with Python, Flask, SQLite, and Pusher

    If you have a web application running out there on the internet, you will need to know where your visitors are coming from, the systems they’re using, and other such things.
    Although you can use services such as Google Analytics, Monster Insights, etc., it’s more fun to build a monitoring system using Python, SQL database, and Pusher for real-time data updates.

    In today’s tutorial, we’ll go over how to create such a tool using Python, Flask, and Pusher. The tutorial is a highly-customized spin-off from a tutorial published on Pusher’s official page.

Programming Leftovers

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Development
  • Eclipse OpenJ9 0.24 Released With A Ton Of Improvements - Phoronix

    In addition to Oracle's GraalVM 21.0 being released this week, the Eclipse Foundation has released OpenJ9 v0.24 as the newest feature release for their high performance JVM.

  • The 10 most popular programming languages, according to Microsoft-owned GitHub [Ed: Why do some sites still reinforce the bogus idea that only projects that Microsoft controls using an oppressive and proprietary monopoly count or exist?]
  • Carlos Garnacho: Threaded input adventures

    Mutter wasn’t always a self-contained compositor toolkit, in the past it used to rely on Clutter and Cogl libraries for all the benefits usually brought by toolkits: Being able to draw things on screen, and being able to receive input.

    In the rise of Wayland, that reliance on an external toolkit drove many of the design decisions around input management, usually involving adding support in the toolkit, and the necessary hooks so Mutter could use or modify the behavior. It was unavoidable that both sides were involved.

    Later on, Mutter merged its own copies of Clutter and Cogl, but the API barrier stayed essentially the same at first. Slowly over time, and still ongoing, we’ve been refactoring Mutter so all the code that talks to the underlying layers of your OS lives together in src/backends, taking this code away from Clutter and Cogl.

  • Partially-Formed @ Meeting C++ 2021 talk is now online

    We will also show how developers that feel uneasy about the partially-formed state can avoid them at little to no cost, neither in code readability, nor performance, and use these examples to propose a new (or old) paradigm for API design: safe and unsafe functions (in the Sean Parent sense).

  • How to implement a DevOps toolchain

    Organizations from all industries and of all sizes strive to deliver quality software solutions faster. This guarantees not only their survival but also success in the global marketplace. DevOps can help them chart an optimal course.

    DevOps is a system where different processes are supported by tools that work in a connected chain to deliver projects on time and at a lower cost.

Programming Leftovers

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Development
  • GNU Parallel 20210122 ('Capitol Riots') released

    GNU Parallel 20210122 ('Capitol Riots') has been released. It is available for download at: http://ftpmirror.gnu.org/parallel/
    Please help spreading GNU Parallel by making a testimonial video like Juan Sierra Pons: http://www.elsotanillo.net/wp-content/uploads/GnuParallel_JuanSierraPons.mp4
    It does not have to be as detailed as Juan's. It is perfectly fine if you just say your name, and what field you are using GNU Parallel for.

  • Maximizing Developer Effectiveness

    Technology is constantly becoming smarter and more powerful. I often observe that as these technologies are introduced an organization’s productivity instead of improving has reduced. This is because the technology has increased complexities and cognitive overhead to the developer, reducing their effectiveness. In this article, the first of a series, I introduce a framework for maximizing developer effectiveness. Through research I have identified key developer feedback loops, including micro-feedback loops that developers do 200 times a day. These should be optimized so they are quick, simple and impactful for developers. I will examine how some organizations have used these feedback loops to improve overall effectiveness and productivity.

  • Open-source Downloads Working Again

    Open-source downloads are working again. Users can install open-source versions of Qt framework and tools via the online installer or download the offline packages.

    Earlier this week our service provider for two important servers related to the open-source downloads had a severe hardware failure in their disk system causing a problem with open-source downloads of Qt. The problem has now been resolved and download systems are working again. Note that there are more than usual delays in using the system due to the load caused by ongoing restoring of other affected systems of the same service provider as well as the load caused by Qt users.

  • Remi Collet: PHP version 7.4.15RC2 and 8.0.2RC1 [Ed: Fedora and Enterprise Linux (RHEL / CentOS)]

    RPM of PHP version 8.0.2RC1 are available as SCL in remi-test repository and as base packages in the remi-php80-test repository for Fedora 31-33 and Enterprise Linux.

    RPM of PHP version 7.4.15RC2 are available as SCL in remi-test repository and as base packages in the remi-test repository for Fedora 32-33 or remi-php74-test repository for Fedora 31 and Enterprise Linux.

  • OASIS Open Establishes European Foundation to Advance Open Collaboration Opportunities

    OASIS Open, the international open source and open standards consortium, is pleased to announce the launch of the OASIS Open Europe Foundation (https://www.oasis-open.eu). The foundation provides a strong and dedicated European focus in setting standards for open collaboration, and allows OASIS to provide long-term sustainability for European Union research projects.

  • International Consortium Bolsters European Focus on Open Source and Open Standards Development

    OASIS Open, the international open source and open standards consortium, is pleased to announce the launch of the OASIS Open Europe Foundation (https://www.oasis-open.eu). The foundation provides a strong and dedicated European focus in setting standards for open collaboration, and allows OASIS to provide long-term sustainability for European Union research projects.

    [...]

    The OASIS Open Europe Foundation’s Board of Directors will include:

  • Laetitia Cailleteau of Accenture (France)
  • Martin Chapman of Oracle (Ireland)
  • Eva Coscia of R2M Solution (Italy)
  • Gershon Janssen, Independent Consultant (Netherlands)
  • Janna Lingenfelder of IBM (Germany)
  • Guy Martin of OASIS Open (United States)
  • Andriana Prentza of the University of Piraeus (Greece)
  • Get Started with MicroPython on Raspberry Pi Pico

    In Get Started with MicroPython on Raspberry Pi Pico, you will learn how to use the beginner-friendly language MicroPython to write programs and connect hardware to make your Raspberry Pi Pico interact with the world around it. Using these skills, you can create your own electro‑mechanical projects, whether for fun or to make your life easier.

  • Perl Weekly Challenge 96: Reverse Words and Edit Distance (and Decorators in Perl)
  • Perl weekly challenge 96
  • Mood Lighting

    The lighting in my bedroom uses Philips Hue bulbs — specifically, the coloured ones. Last night, I decided it would be nice to set the three lights in my bedroom to cycle slowly through a set of warm colours using a script.

    I didn't want harsh transitions from one colour to the next, but for the lighting to fade from one colour to the next in a smooth gradient. Also, I didn't want the three bulbs to all be the exact same colour, but wanted each bulb to be at different stage in the cycle, like they're "chasing" each other through the colours.

    So I whipped up a quick script. It requires the command-line tool hueadm to be installed and set up before we start. You can run hueadm lights to get a list of available lights, and in particular, their ID numbers.

  • This Week in Rust 374

Programming Leftovers

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Development
  • What is your favorite Linux scripting or programming language? | Enable Sysadmin

    Of all the scripting and programming language options available to you on the Linux platform, which one is your favorite?

  • When costs are nonlinear, keep it small.

    It shows Preventive Maintenance as a series of small costs. Minor repairs are a series of bigger costs, and major repairs are much bigger than that. Every maintenance delayed escalates into a minor repair and then a major repair — costs increase nonlinearly with time delay.

  • Old compilers and old bugs

    The kernel project goes out of its way to facilitate building with older toolchains. Building a kernel on a new system can be enough of a challenge as it is; being forced to install a custom toolchain first would not improve the situation. So the kernel developers try to keep it possible to build the kernel with the toolchains shipped by most distributors. There are costs to this policy though, including an inability to use newer compiler features. But, as was seen in a recent episode, building with old compilers can subject developers to old compiler bugs too.

    On January 5, Russell King reported on a problem he had been chasing for a long time. Some of his 64-bit Arm systems running 5.4 or later kernels would, on rare occasion, report a checksum failure on the ext4 root filesystem. It could take up to three months of uptime for the problem to manifest itself, making it, as King described it, "unrealistic to bisect". He had, however, found a way to more reliably reproduce the failure, making the task of finding out when the problem was introduced plausible, at least.

    Starting with King's findings, a number of developers working in the Arm subsystem looked into the issue; their efforts seemed to point out this commit as the culprit. That change, applied in 2019, relaxed the memory barriers used around I/O accessors, optimizing accesses to I/O memory. Reverting this patch made the problem go away.

  • Callback Function in C++ – Linux Hint

    A callback function is a function, which is an argument, not a parameter, in another function. The other function can be called the principal function. So two functions are involved: the principal function and the callback function itself. In the parameter list of the principal function, the declaration of the callback function without its definition is present, just as object declarations without assignment are present. The principal function is called with arguments (in main()). One of the arguments in the principal function call is the effective definition of the callback function. In C++, this argument is a reference to the definition of the callback function; it is not the actual definition. The callback function itself is actually called within the definition of the principal function.

    The basic callback function in C++ does not guarantee asynchronous behavior in a program. Asynchronous behavior is the real benefit of the callback function scheme. In the asynchronous callback function scheme, the result of the principal function should be obtained for the program before the result of the callback function is obtained. It is possible to do this in C++; however, C++ has a library called future to guarantee the behavior of the asynchronous callback function scheme.

  • Regarding the closure of rt.cpan.

    Let me preface this short post with this, I don't have the solution to this problem. Perhaps there is someone in the wider Perl space who is well placed to pick this up, but there seems to be little going on in terms of community engagement.

    In the first week of 2021 I noticed a link to this sunset message for rt.cpan behind displayed on the rt.cpan homepage. Firstly I believe the notification on the page could be highlighted better, grey on grey, on a page with lots of grey isn't exactly eye catching.

    At the time the linked article didn't contain much information, besides a date. It has since been updated with links to resources to migrate tickets elsewhere.

    A reply to my post in the perlmonks news section was concerning to me, I shortly found the infrastructure working group post on topicbox (which I find no link to on any of the perl websites, or release documentation). This thread was concerning in so much as a single volunteer has decided to step back, which is of course fine, but it doesn't seem like the option of asking the wider community if anyone would be willing to step up and take it over has been explored. It doesn't even seem to be being openly discussed.

  • Perl weekly challenge 096 - Raku
  • GNU Linux Bash – script for troubleshoot long term test testing network internet connection connectivity

    this script is intended for long term testing of reliability of network connection/connectivity

Python Programming

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Development
  • Python Deque – Linux Hint

    A deque means double-ended-queue with the addition of elements from any end; users can also remove elements from any end. This module comes from the collections library and is implemented using this module. It is generally preferable over the list where we need to have a faster method to append operations. The additions and removal can be done from both container ends. Users can add the values in the deque or remove them from both sides. They can even reverse the entire deque. The tutorial will cover all possible use cases along with elaborate examples for the ease of the users.

    We ideally use the latest version of Python for implementation that is Python x3.8, but if anyone does not have the latest version, even then they can implement it on their versions. It will generate similar results.

  • Python Eclipse and PyDev Installation – Linux Hint

    Eclipse is a framework for interactive development that is being used in software development. It comprises a base platform and an optimized environment customization plug-in framework. On the other hand, PyDev is a third-party module or plug-in, which is used in Eclipse. It is an optimized development platform that facilitates code refactoring, graphic debug, code inspection, and other functions for Python coding. If you are searching for a guide to install and configure both the tools, then you are in the right place.

  • Python Enumerate Function Tutorial – Linux Hint

    Enumerate is a Python built-in method. Enumerate() takes a set (e.g. a tuple) and returns it like an entity of enumeration. In a small statement, its significance can not be described. Although it is unfamiliar to most beginners, as well as some proficient programmers. It enables one to loop and provide an auto-counter about something. A counter is inserted by the enumerate() method as the enumerate object key.

  • Python Map() Function Tutorial – Linux Hint

    Often you may face cases where you need to execute the same procedure on all the objects of an iterable input to generate a new iterable. Python’s map() is an integrated method that enables all the objects to be interpreted and translated into an iterable instead of an explicit loop, usually referred to as mapping. Using a Python for loop is the simplest but using the map, you can also solve this issue without the need for an explicit loop(). When you’re about to implement a transformation method to each object in an iterable, map() helps translate them into a fresh iterable. One of the methods which are promoting a functional programming type in Python is a map(). In this guide, you will learn about how the map() method works with different object types.

  • What is Pony ORM and How to Get Started?

    Pony ORM is a Python programming language directory that enables people to work comfortably with objects kept as tuples in a relational database system. It enables you to deal with the information of the databank, in the form of substances/objects. In the database, there are tables having tuples of data. Conversely, when it is possible to view the data obtained from the databank in object form, it is far more useful when writing the code in an advanced-level object-oriented semantic. If you wish to work with Pony ORM, you have to go through the below-appended steps thoroughly.

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Free Software Leftovers

  • Ingo Juergensmann: Migrating from Drupal to WordPress

    If you can read this on planet.debian.org then migrating my blog from Drupal to WordPress was successful and the feed has been successfully changed by the Debian Planet Maintainers (thanks!). I’ve been a long term Drupal user. I think I started to use Drupal since it was included in Debian. At some point Drupal was removed from Debian and I started to use Serendipity instead. Later Drupal was included in Debian again and I moved back to Drupal. I think this must have been around Drupal 4 or Drupal 5. No idea. I even became active in the Drupal community and went to one of the first Drupal barcamps in Germany, namely in Cologne. This was shortly before Dries Buytaert started a business off of Drupal and went to the USA. I met with many devs of Drupal in Cologne and enjoyed the community and started with others a local Drupal User Group in Rostock. [...] So, after all the years my Drupal journey will come to an end. It was a long time with you. Sometimes joyful, sometimes painful. I wish you all the best, Drupal!

  • The round-the-world trip to fix a bug

    Mrs. Vera Cavalcante (@veracape), from Brazil, a long-time contributor for the Portuguese documentation on LibreOffice, was reviewing the translation of the Calc Guide and double-checking the translated text, with respect to the current user interface and the Help pages. Vera noticed that the Help pages on conditional formatting were not correct any more, and reported in the Brazilian team Telegram group (Bugzilla is still very hard for non-native English speakers).…

  • Red Kubes Container Platform Flies Open Source Flag

    Red Kubes, a Dutch-based startup, open sourced a free community edition of its Otomi Container Platform in a bid to remedy the ongoing complexity surrounding Kubernetes configurations. The scalability, agility, and speed-to-market advantages that Kubernetes offers have been handsome enough to capture a growing share of the enterprise market, but this very strength can become an Achilles heel for container deployments. In this sense, it’s far too easy – and common – to create thousands or even tens of thousands of containers across applications. Not only does this create an operational money pit, but management becomes a herculean feat to any container newbie.

  • The Apache Software Foundation Announces Apache® ECharts™ as a Top-Level Project

    The Apache Software Foundation (ASF), the all-volunteer developers, stewards, and incubators of more than 350 Open Source projects and initiatives, announced today Apache® ECharts™ as a Top-Level Project (TLP). Apache ECharts is an intuitive, interactive, and powerful charting and visualization library ideally suited for commercial-grade presentations. The project originated in 2013 at Baidu and entered the Apache Incubator in January 2018.

  • Shots fired in disputes over OSS-as-a-Service

    Cloud services are the great disruptor of both IT organizations and vendors, and wrapping open source software around a service is the latest flashpoint. The open source development model has proven to be an incredible incubator of innovative software by democratizing and distributing the conception, design, implementation and debugging of new titles, advantages that were thoroughly explored more than two decades ago in the book, The Cathedral and the Bazaar. Although open source has since been adopted, encouraged and sponsored by every major software company, its origins were decidedly non-commercial with utopian overtones of liberating code from the tyranny of proprietary shackles. The earliest open source projects, notably Gnu Emacs and other tools from the Gnu Project, embraced this idealistic ethos with a restrictive, comprehensive license, GPL, that applies to derivative work using the code.

  • AWS to Fork Elasticsearch as Elastic Moves Away from Open Source

    Elastic’s license change from open source ALv2 to SSPL appears to have moved Amazon Web Services to “launch new forks of both Elasticsearch and Kibana.” Elasticsearch’s move towards the more restrictive Server Side Public License has already begun to ruffle feathers among developers.

Programming Leftovers

  • Excellent Free Tutorials to Learn Tcl - LinuxLinks

    Tcl (Tool Command Language) is a dynamic programming/scripting language based on concepts of Lisp, C, and Unix shells. Here's our recommended free tutorials to learn Tcl.

  • ROC and Precision-Recall curves - How do they compare?

    Both curves offer two useful information: how to choose the positive class prediction threshold and what is the overall performance of the classification model. The former is determined by selecting the threshold which yield the best tradeoff, in adequation with the prediction task and operational needs. The latter is done by measuring the area under the curves which informs about how good the model is, because by measuring the area under the curves, one computes the overall probability that a sample from the negative class has a lower probability than a sample from the positive class. With scikit-learn, the values can be computed either by using the roc_auc attribute of the object returned by plot_roc_curve() or by calling roc_auc_score() directly for ROC curves and by using the average_precision attribute of the object returned by plot_precision_recall_curve() or by calling average_precision_score() directly for PR curves.

  • Write GIMP scripts to make image processing faster | Opensource.com

    Some time ago, I wanted to give a blackboard-style look to a typeset equation. I started playing around with the GNU Image Manipulation Program (GIMP) and was satisfied with the result. The problem was that I had to perform several actions on the image, I wanted to use this style again, and I did not want to repeat the steps for all the images. Besides, I was sure that I would forget them in no time.

  • Bash wait Command | Linuxize

    wait is a command that waits for the given jobs to complete and returns the exit status of the waited for command. Since the wait command affects the current shell execution environment, it is implemented as a built-in command in most shells. In this article, we’ll explore the Bash built-in wait command.

  • Santiago Zarate: Cron do not send me empty emails
  • Rust & the case of the disappearing stack frames | Inside Rust Blog

    Now that the FFI-unwind Project Group has merged an RFC specifying the "C unwind" ABI and removing some instances of undefined behavior in the "C" ABI, we are ready to establish new goals for the group. Our most important task, of course, is to implement the newly-specified behavior. This work has been undertaken by Katelyn Martin and can be followed here.

Open Hardware: Raspberry Pi, Arduino, Thomas Petazzoni (Bootlin) on Training

  • Qsync fixed on the Pi4 and FF compiled

    The Raspberry Pi4 does not have a hardware battery-backed clock, so relies on getting the date and time from an Internet time server. In EasyOS, Qsync is the utility that does that. At first bootup, QuickSetup has a checkbox to enable getting time from the Internet, which will launch Qsync. At first bootup on the Pi4, if you are going to connect to Internet via wifi, not ethernet, then there won't be an immediate Internet access. No problem, Qsync will run once the Internet connection is established. Qsync will run just once at bootup and after Internet connection. That's fine, but I couldn't understand why it would suddenly stop working. Then discovered that /etc/init.d/qsync was getting its executable-flag cleared.

  • Arduino Blog » This children’s console looks like something straight out of a superhero’s lair

    Kids have wonderful imaginations, and to help students at a primary school have a super time, creator “palladin” was asked to construct a console for them to use. The device features a variety of lights and sci-fi additions, including glowing “reactor” tubes that diffuse light using hair gel and a “memory bank” that emits flashing patterns for a 1950s supercomputer look.

  • Arduino Blog » This pen plotter draws detailed maps the size of walls

    Christopher Getschmann wanted a wall-sized map of the world. He soon realized, however, that it’s tough to actually buy such a map that’s both beautiful and detailed enough to satisfy his cartographic tastes. While many would simply move on to the next “thing,” Getschmann instead took things into his own hands, and built a pen plotter specifically to draw massive 2×3 meter map for his wall.

  • New training course: embedded Linux boot time optimization

    For many embedded products, the issue of how much time it takes from power-on to the application being fully usable by the end-user is an important challenge. Bootlin has been providing its expertise and experience in this area to its customers for many years through numerous boot time optimization projects, and we have shared this knowledge through a number of talks at several conferences over the past years. We are now happy to announce that we have a new training course Embedded Linux boot time optimization, open for public registration. This training course was already given to selected Bootlin customers and is now available for everyone.

Red Hat/Fedora Leftovers

     
  • A brief introduction to Ansible roles for Linux system administration

    In this part one of two articles, learn to use rhel-system-roles with your Ansible deployment to better manage functionality such as network, firewall, SELinux, and more on your Red Hat Enterprise Linux servers.

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  • From Docker Compose to Kubernetes with Podman | Enable Sysadmin

    Use Podman 3.0 to convert Docker Compose YAML to a format Podman recognizes.

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  • Fedora Community Blog: Software Management (RPM, DNF) 2020 retrospective

    On behalf of the RPM and DNF teams, I would like to highlight changes that have appeared in our packages in 2020. Thanks everyone for your bug reports and patches!

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  • Application and data resiliency for Kubernetes

    Using tools like Red Hat OpenShift and Red Hat OpenShift Container Storage, organizations are developing and deploying more stateful applications and microservices at an accelerating pace. According to a recent Enterprise Strategy Group (ESG) research study, 41% of companies currently use containers for production applications. Another 33% use containers for dev/test and pre-production only but plan to use containers for production applications in the next 12 months.

  • Red Hat Introduces Data Resilience for Enterprise Kubernetes Applications

    Red Hat, Inc., the world's leading provider of open source solutions, today introduced new data resilience capabilities for cloud-native workloads with the release of Red Hat OpenShift Container Storage 4.6. This offering from Red Hat Data Services enables customers to extend their existing data protection solutions and infrastructure to enhance data resilience for cloud-native workloads across hybrid and multicloud environments.

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  • Why Red Hat killed CentOS—a CentOS board member speaks

    This morning, The Register's Tim Anderson published excerpts of an interview with the CentOS project's Brian Exelbierd. Exelbierd is a member of the CentOS board and its official liaison with Red Hat. Exelbierd spoke to Anderson to give an insider's perspective on Red Hat's effective termination of CentOS Linux in December, in which the open source giant announced CentOS Linux was to be deprecated immediately—with security upgrades to CentOS Linux 8 ending later in 2021 rather than the 2029 end of support date CentOS users expected.