How to capture background requests and responses in Puppeteer?

When web scraping using Puppeteer and Python to capture background requests and responses we can use the page.on() method to add callbacks on request and response events:

const puppeteer = require('puppeteer');

function run() {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  // capture background requests:
  await page.setRequestInterception(true);
  page.on('request', request => {
    if (request.resourceType() === 'xhr') {
      console.log(request):
      // we can block these requests with:
      request.abort();
    } else {
      request.continue();
    }
  });
  // capture background responses:
  page.on('response', response => {
    if (response.resourceType() === 'xhr') {
      console.log(response);
    }
  })
  await browser.close();
}

run();

Often these background requests can contain important dynamic data. Blocking some requests can also reduce the bandwidth used by the scraper, for more on that see How to block resources in Puppeteer?