Proxy Builder

To scrape Binance courses data in Python, you can use web scraping libraries such as BeautifulSoup and requests. Here's an example using BeautifulSoup to scrape Binance courses

Install required libraries:

pip install beautifulsoup4 requests

Write the scraping code:

import requests
from bs4 import BeautifulSoup

def scrape_binance_courses():
    url = 'https://www.binance.com/en/academy/courses'

    # Send a GET request to the URL
    response = requests.get(url)

    # Check if the request was successful (status code 200)
    if response.status_code == 200:
        soup = BeautifulSoup(response.text, 'html.parser')

        # Find the container containing course information
        course_container = soup.find('div', {'class': 'css-7sfsgn'})

        if course_container:
            # Extract course details
            courses = course_container.find_all('div', {'class': 'css-1jiwjuo'})
            
            for course in courses:
                course_title = course.find('div', {'class': 'css-1mg41yd'}).text
                course_description = course.find('div', {'class': 'css-1q62c8m'}).text

                print(f"Title: {course_title}\nDescription: {course_description}\n")

        else:
            print("Course container not found.")
    else:
        print(f"Failed to retrieve the webpage. Status code: {response.status_code}")

# Run the scraping function
scrape_binance_courses()

This example sends a GET request to the Binance Academy courses page, parses the HTML content using BeautifulSoup, and extracts course details such as title and description.

Run the code:

python your_script_name.py

In the User Datagram Protocol (UDP), dynamic ports are assigned using a process called ephemeral port allocation. UDP is a connectionless protocol, which means that it does not establish a dedicated connection between the sender and receiver, as the Transmission Control Protocol (TCP) does. Instead, UDP sends data packets directly to the destination, and the receiver is responsible for acknowledging receipt or requesting retransmission if needed.

In UDP, both the sender and receiver have a pair of ports: one for the source and one for the destination. The source port is assigned by the sender, while the destination port is assigned by the receiver. When a connection is established, the sender assigns an ephemeral port to itself and sends the data to the destination port specified by the receiver.

The assignment of dynamic ports in UDP is typically managed by the operating system. The process generally follows these steps:

1. Ephemeral port allocation: The operating system maintains a pool of available ephemeral ports, which are typically in the range of 49152 to 65535. When a UDP connection is initiated, the operating system assigns an available ephemeral port from this range to the sender.

2. Port reuse: Once a UDP connection is closed, the ephemeral port is returned to the pool of available ports. This allows the port to be reused for subsequent connections, ensuring efficient use of the limited range of high-numbered ports.

3. Port randomization: Some operating systems implement port randomization to prevent certain types of denial-of-service (DoS) attacks. In this case, the operating system may assign an ephemeral port that is slightly higher than the requested port, adding a small random offset to the port number.

4. Destination port assignment: The destination port is assigned by the receiver and is typically determined by the application or service that the receiver is running. The destination port can be a well-known port (below 1024) or a registered port (1024-49151), or it can be a dynamic or private port (49152-65535).

In summary, dynamic ports in UDP are assigned using a combination of ephemeral port allocation and destination port assignment. The process is managed by the operating system and is designed to ensure efficient and secure communication between devices.

To send a UDP request to a STUN server in C++, you can use the following example code. This example uses the boost::asio library for handling asynchronous I/O operations and boost::beast for handling UDP communication. Make sure you have the Boost library installed on your system before running this code.

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

namespace http = boost::beast::http;

using tcp = boost::asio::ip::tcp;
using udp = boost::asio::ip::udp;

int main(int argc, char* argv[]) {
  if (argc != 3) {
    std::cerr << "Usage: stun_udp_request  " << std::endl;
    return EXIT_FAILURE;
  }

  boost::asio::io_context ioc;
  udp::resolver resolver(ioc);
  udp::resolver::results_type results = resolver.resolve(argv[1], argv[2]);

  if (results.empty()) {
    std::cerr << "Cannot resolve: " << argv[1] << ":" << argv[2] << std::endl;
    return EXIT_FAILURE;
  }

  udp::socket udp_socket(ioc);
  udp_socket.connect(results.begin()->endpoint());

  // Prepare the STUN Binding Request
  std::string stun_request =
      "BINDING_REQUEST\r\n"
      "MIXED_RELAY\r\n"
      "USER-AGENT: STUN-UDP-Example\r\n"
      "\r\n";

  // Send the STUN Binding Request
  boost::system::error_code ignored_error;
  udp_socket.send_to(boost::asio::buffer(stun_request), results.begin()->endpoint(), 0, ignored_error);

  // Receive the STUN Binding Response
  boost::beast::flat_buffer buffer;
  http::response response;
  udp_socket.receive_message(buffer, response);

  // Print the STUN Binding Response
  std::cout << "STUN Binding Response:\n";
  std::cout << response.what() << std::endl;

  return EXIT_SUCCESS;
}

To compile the example, you can use the following command:

g++ -std=c++17 -o stun_udp_request stun_udp_request.cpp -lboost_system -lboost_as

If you can't download images in Scrapy:

- Check the image pipeline configuration in settings.py.
- Verify HTTPS compatibility and install the certifi package if necessary.
- Confirm the correctness of XPath or CSS selectors for image URLs.
- Ensure image URLs are in the correct format; log URLs for inspection.
- Handle redirects by setting REDIRECT_ENABLED = True.
- Check and set appropriate HTTP headers in your Scrapy spider.
- Adjust the CONCURRENT_REQUESTS setting to avoid server restrictions.
- Verify correct configuration of the ImagesPipeline.
- Inspect the downloaded images in the specified IMAGES_STORE directory.
- Implement exception handling in your spider to catch download errors.

The reason for the lack of connection to the network can be due to incorrect proxy settings, that is, incorrect IP addresses were entered or specified, or the server simply does not work. Users also often forget that proxy settings must be disabled.