Querying data with Pandas .query() method

Single condition filtering

# importing pandas package 
import pandas as pd 

# making data frame from csv file 
data = pd.read_csv("employees.csv") 

# replacing blank spaces with '_' 
data.columns =[column.replace(" ", "_") for column in data.columns] 

# filtering with query method 
data.query('Senior_Management == True', inplace = True) 

# display 
data 

Multiple condition filtering

# importing pandas package 
import pandas as pd 

# making data frame from csv file 
data = pd.read_csv("employees.csv") 

# replacing blank spaces with '_' 
data.columns =[column.replace(" ", "_") for column in data.columns] 

# filtering with query method 
data.query('Senior_Management == True
      and Gender =="Male" and Team =="Marketing"
      and First_Name =="Johnny"', inplace = True) 

# display 
data 

References
https://www.geeksforgeeks.org/python-filtering-data-with-pandas-query-method/

Template Matching On Images C# using OpenCV

Image<Bgr, byte> Image1 = new Image<Bgr, byte>(Properties.Resources.Image1); //Your first image
        Image<Bgr, byte> Image2 = new Image<Bgr, byte>(Properties.Resources.Image2); //Your second image

        double Threshold = 0.8; //set it to a decimal value between 0 and 1.00, 1.00 meaning that the images must be identical

        Image<Gray, float> Matches = Image1.MatchTemplate(Image2, TemplateMatchingType.CcoeffNormed);

        for (int y = 0; y < Matches.Data.GetLength(0); y++)
        {
            for (int x = 0; x < Matches.Data.GetLength(1); x++)
            {
                 if (Matches.Data[y, x, 0] >= Threshold) //Check if its a valid match
                 {
                     //Image2 found within Image1
                 }
            }
        }

References
https://stackoverflow.com/questions/39570033/template-matching-on-images-c-sharp

Move and Click Mouse in C#

[DllImport("user32.dll")]
public static extern void mouse_event(MouseEventFlags dwFlags, uint dx, uint dy, uint dwData, MouseEventDataXButtons dwExtraInfo);

[DllImport("User32.Dll")]
public static extern long SetCursorPos(int x, int y);
[Flags]
public enum MouseEventFlags : uint
{
    LEFTDOWN = 0x00000002,
    LEFTUP = 0x00000004,
    MIDDLEDOWN = 0x00000020,
    MIDDLEUP = 0x00000040,
    MOVE = 0x00000001,
    ABSOLUTE = 0x00008000,
    RIGHTDOWN = 0x00000008,
    RIGHTUP = 0x00000010,
    WHEEL = 0x00000800,
    XDOWN = 0x00000080,
    XUP = 0x00000100
}

//Use the values of this enum for the 'dwData' parameter
//to specify an X button when using MouseEventFlags.XDOWN or
//MouseEventFlags.XUP for the dwFlags parameter.
public enum MouseEventDataXButtons : uint
{
    XBUTTON1 = 0x00000001,
    XBUTTON2 = 0x00000002
}
public static void MoveMouse(int x, int y)
{
    PInvoke.SetCursorPos(x, y);
}

public static void ClickMouse(int x, int y)
{
    PInvoke.mouse_event(MouseEventFlags.LEFTDOWN | MouseEventFlags.ABSOLUTE, (uint)x, (uint)y, 0, 0);
    Thread.Sleep(10);
    PInvoke.mouse_event(MouseEventFlags.LEFTUP | MouseEventFlags.ABSOLUTE, (uint)x, (uint)y, 0, 0);
}

References
https://stackoverflow.com/questions/13520705/move-mouse-to-position-and-left-click
http://www.pinvoke.net/default.aspx/user32.mouse_event
https://stackoverflow.com/questions/8050825/how-to-move-mouse-cursor-using-c
https://www.pinvoke.net/default.aspx/user32.setcursorpos

Take Screenshot in C#

First Set Process DPI Aware:

Get Screen Size on C#
https://pupli.net/2020/03/get-screen-size-on-c/

Install-Package System.Drawing.Common -Version 7.0.0

Take screenshot and save to file

using System;
using System.Drawing;
using System.Windows.Forms;

namespace ScreenshotExample
{
    class Program
    {
        static void Main(string[] args)
        {
            // Get the bounds of the screen
            Rectangle bounds = Screen.PrimaryScreen.Bounds;

            // Create a bitmap object to store the screenshot
            using (Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height))
            {
                // Create a graphics object from the bitmap
                using (Graphics g = Graphics.FromImage(bitmap))
                {
                    // Capture the screen
                    g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
                }

                // Save the screenshot as a PNG file
                bitmap.Save("screenshot.png");
            }

            Console.WriteLine("Screenshot saved as screenshot.png");
        }
    }
}

Take screenshot and save to memory

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

namespace ScreenshotToMemory
{
    class Program
    {
        static void Main(string[] args)
        {
            // Get the bounds of the screen
            Rectangle bounds = Screen.PrimaryScreen.Bounds;

            // Create a bitmap object to store the screenshot
            using (Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height))
            {
                // Create a graphics object from the bitmap
                using (Graphics g = Graphics.FromImage(bitmap))
                {
                    // Capture the screen
                    g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
                }

                // Store the screenshot in memory using MemoryStream
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);

                    // Convert the MemoryStream to byte array
                    byte[] screenshotBytes = memoryStream.ToArray();

                    // Now the screenshot is stored in screenshotBytes, you can use it as needed
                    // For demonstration, let's output the length of the byte array
                    Console.WriteLine($"Screenshot captured. Byte array length: {screenshotBytes.Length}");
                }
            }
        }
    }
}

 

Get Screen Size on C#

The process is running under DPI virtualization. So we should apply the DPI aware manifest option to stop DPI virtualization

[DllImport("user32.dll", SetLastError=true)]
static extern bool SetProcessDPIAware();

Then

public enum SystemMetric
{
    VirtualScreenWidth = 78, // CXVIRTUALSCREEN 0x0000004E 
    VirtualScreenHeight = 79, // CYVIRTUALSCREEN 0x0000004F 
}

[DllImport("user32.dll")]
public static extern int GetSystemMetrics(SystemMetric metric);

public static Size GetVirtualDisplaySize()
{
    var width = GetSystemMetrics(SystemMetric.VirtualScreenWidth);
    var height = GetSystemMetrics(SystemMetric.VirtualScreenHeight);

    return new Size(width, height);
}

References
https://stackoverflow.com/questions/28339257/getsystemmetrics-and-tscreen-returns-wrong-value
https://www.pinvoke.net/default.aspx/user32/SetProcessDPIAware.html
https://stackoverflow.com/questions/1317235/c-get-complete-desktop-size
https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setprocessdpiaware

Set Up WireGuard VPN on Ubuntu 18.04

Server Installation

wget https://raw.githubusercontent.com/complexorganizations/wireguard-install/master/wireguard-server.sh -P /etc/wireguard/
bash /etc/wireguard/wireguard-server.sh

Client Installation

wget https://raw.githubusercontent.com/complexorganizations/wireguard-install/master/wireguard-client.sh -P /etc/wireguard/
bash /etc/wireguard/wireguard-client.sh

Or

apt-get update
apt-get install software-properties-common -y
add-apt-repository ppa:wireguard/wireguard -y
apt-get update
apt-get install linux-headers-"$(uname -r)" -y
apt-get install wireguard qrencode haveged resolvconf -y

Run Client

# Install the config file to the WireGuard configuration directory on your
# Linux client:
sudo install -o root -g root -m 600 <username>.conf /etc/wireguard/wg0.conf

# Start the WireGuard VPN:
sudo systemctl start wg-quick@wg0

# Check that it started properly:
sudo systemctl status wg-quick@wg0

# Verify the connection to the AlgoVPN:
sudo wg

# See that your client is using the IP address of your AlgoVPN:
curl ipv4.icanhazip.com

# Optionally configure the connection to come up at boot time:
sudo systemctl enable wg-quick@wg0

References
https://github.com/complexorganizations/wireguard-install
https://trailofbits.github.io/algo/client-linux-wireguard.html

Pass a value to the Resolver on Angular

{
  path: 'project/:id',
  component: ProjectComponent,
  resolve: { data: DataResolver },
  data: { path: 'project/:id' }
}

class DataResolve implements Resolve<string> {
  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
    return route.data['path'];
  }
}
return new Observable<Item>(subscriber => {
  // tslint:disable-next-line
  const itemId = route.params.id;
  this.db.findItemByItemId2(itemId).subscribe(value => {
    subscriber.next(value);
    subscriber.complete();
  });
});

References
https://stackoverflow.com/questions/40297165/angular-2-pass-a-value-to-the-route-data-resolve/49171861