Simplifying Asynchronous Task Execution with Celery in Python

- by mahmood

Setting up the Celery Application

First, we need to set up our Celery application. This involves specifying the message broker and defining tasks. A message broker is a mechanism responsible for transferring data between the application and Celery workers. In our example, we use RabbitMQ as the broker.

Here is the code snippet for setting up a Celery application, saved in a file named tasks.py:

from celery import Celery

# Create a Celery instance
app = Celery("tasks", broker='amqp://username:password@localhost')

# Define a simple task to add two numbers
@app.task
def add(x, y):
    return x + y

In this setup, Celery is initialized with a name (“tasks”) and a broker URL, which includes the username, password, and server location (in this case, localhost for local development).

Defining a Task

We define a simple task using the @app.task decorator. This task, add, takes two parameters, x and y, and returns their sum. The decorator marks this function as a task that Celery can manage.

Calling the Task Asynchronously

To call our add task asynchronously, we use the following code snippet in main.py:

from tasks import add

# Call the add task asynchronously
result = add.delay(1, 2)
print("Task sent to the Celery worker!")

The delay method is a convenient shortcut provided by Celery to execute the task asynchronously. When add.delay(1, 2) is called, Celery sends this task to the queue and then it’s picked up by a worker.

Running Celery Workers

To execute the tasks in the queue, we need to run Celery workers. Assuming you’ve activated a virtual environment, you can start a Celery worker using the following command:

.venv\Scripts\celery.exe -A tasks worker --loglevel=info

This command starts a Celery worker with a log level of info, which provides a moderate amount of logging output. Here, -A tasks tells Celery that our application is defined in the tasks.py file.

Fedora 40 Post Install

- by mahmood

Making dnf a little faster

sudo nano /etc/dnf/dnf.conf
max_parallel_downloads=8

Firmware

sudo fwupdmgr get-devices 
sudo fwupdmgr refresh --force 
sudo fwupdmgr get-updates 
sudo fwupdmgr update

Media Codecs

sudo dnf groupupdate 'core' 'multimedia' 'sound-and-video' --setopt='install_weak_deps=False' --exclude='PackageKit-gstreamer-plugin' --allowerasing && sync
sudo dnf swap 'ffmpeg-free' 'ffmpeg' --allowerasing
sudo dnf install gstreamer1-plugins-{bad-\*,good-\*,base} gstreamer1-plugin-openh264 gstreamer1-libav --exclude=gstreamer1-plugins-bad-free-devel ffmpeg gstreamer-ffmpeg
sudo dnf install lame\* --exclude=lame-devel
sudo dnf group upgrade --with-optional Multimedia

H/W Video Acceleration

sudo dnf install ffmpeg ffmpeg-libs libva libva-utils
sudo dnf swap libva-intel-media-driver intel-media-driver --allowerasing

Set Hostname

hostnamectl set-hostname YOUR_HOSTNAME

Disable Mitigations

sudo grubby --update-kernel=ALL --args="mitigations=off"

Modern Standby

sudo grubby --update-kernel=ALL --args="mem_sleep_default=s2idle"

Enable nvidia-modeset

sudo grubby --update-kernel=ALL --args="nvidia-drm.modeset=1"

Disable NetworkManager-wait-online.service

sudo systemctl disable NetworkManager-wait-online.service

Disable SELinux

sudo grubby --update-kernel ALL --args selinux=0
sudo nano /etc/selinux/config

SELINUX=disabled

References
https://github.com/devangshekhawat/Fedora-40-Post-Install-Guide

Disabling UAC in Windows 11 using the registry

- by mahmood
  1. Press Windows Key + R to open the Run dialog.
  2. Type regedit and press Enter.
  3. Navigate to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
  1. In the right-hand pane, find the value named EnableLUA.
  2. Double-click on EnableLUA.
  3. Change the Value data from 1 to 0.
  4. Click OK to save the changes.
  5. Restart your computer for the changes to take effect.

Hide a User from the Windows Login Screen

- by mahmood

Getting the exact username

  1. Press Windows Key + R to open the Run dialog.
  2. Type netplwiz and press Enter.
  3. The User Accounts window will list all user accounts on your Windows machine. The usernames are displayed in the “User name” column.

Using the Registry Editor

  1. Open the Registry Editor:

    • Press the Windows key + R.
    • Type “regedit” and press Enter.

  2. Navigate to the Winlogon Key:

    • Go to this path: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

  3. Create SpecialAccounts and UserList Keys:

    • Right-click on “Winlogon” and select New -> Key. Name it SpecialAccounts.
    • Right-click on “SpecialAccounts” and select New -> Key. Name it UserList.

  4. Create a DWORD Value:

    • Right-click within the “UserList” key.
    • Select New -> DWORD (32-bit) Value.
    • Name the DWORD the exact username of the account you want to hide.
    • Double-click the new DWORD and set its value data to 0.

  5. Restart: Close the Registry Editor and restart your computer.

Deploy applications in Run as Administrator mode in Windows using Visual Studio and Inno Setup

- by mahmood

Add the following line in your [Setup] section. This is the primary way to indicate that your installer requires administrative rights.

[Setup]
...
PrivilegesRequired=admin
...

Consider embedding an appropriate manifest into your application’s executable to have it automatically request elevation when executed outside the installer. This can provide a more seamless experience for the user.

1. Create the Manifest File:

  • Right-click on your project in the Solution Explorer and select Add -> New Item….
  • Choose Application Manifest File (it might be under the General category).
  • The default name is typically app.manifest. Keep this name or adjust it if necessary.

2. Modify the Manifest:

  • Open the newly created app.manifest file. The default content will be similar to this:

<?xml version="1.0" encoding="utf-8"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
  <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/>
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
    <security>
      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v1">
        </requestedPrivileges>
    </security>
  </trustInfo>
</assembly>
  • Inside the <requestedPrivileges> element, add the following line:
<requestedExecutionLevel  level="requireAdministrator" uiAccess="false" />

3. Embed the Manifest:

The manifest is now created, but you need to tell Visual Studio to embed it into your executable:

  • Right-click on your project and select Properties.
  • Go to the Application tab.
  • Under Manifest, select Embed manifest with default settings.

Build the Project:

Rebuild your project. The generated executable will now have the UAC manifest embedded, causing your application to request administrative privileges when run.

Handle Clipboard Paste in WPF

- by mahmood 
public YourWindow()
{
    InitializeComponent();

    // "yourTextBox" is your TextBox
    DataObject.AddPastingHandler(yourTextBox, OnPaste);
}

private void OnPaste(object sender, DataObjectPastingEventArgs e)
{
    var isText = e.SourceDataObject.GetDataPresent(DataFormats.UnicodeText, true);
    if (!isText) return;

    var text = e.SourceDataObject.GetData(DataFormats.UnicodeText) as string;
    // Manipulate the text here
    text = text.Replace("oldValue", "newValue"); // Example manipulation

    // Set the new data
    e.DataObject = new DataObject(DataFormats.UnicodeText, text);
}

Note that this event is triggered after the user initiates the paste command but before the content is actually pasted into the TextBox, allowing you to modify or cancel the paste operation.

References
https://stackoverflow.com/questions/3061475/paste-event-in-a-wpf-textbox

Install chromedriver Automatically while using Selenium in C#

- by mahmood 
PM> Install-Package WebDriverManager
using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using WebDriverManager;
using WebDriverManager.DriverConfigs.Impl;

namespace Test
{
    [TestFixture]
    public class Tests
    {
        private IWebDriver _webDriver;

        [SetUp]
        public void SetUp()
        {
            new DriverManager().SetUpDriver(new ChromeConfig());
            _webDriver = new ChromeDriver();
        }

        [TearDown]
        public void TearDown()
        {
            _webDriver.Quit();
        }

        [Test]
        public void Test()
        {
            _webDriver.Navigate().GoToUrl("https://www.google.com");
            Assert.True(_webDriver.Title.Contains("Google"));
        }
    }
}

References
https://github.com/rosolko/WebDriverManager.Net