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Showing posts with the label Web Scraping

Crawling Multiple URLs In A Loop Using Puppeteer

Answer : map , forEach , reduce , etc, does not wait for the asynchronous operation within them, before they proceed to the next element of the iterator they are iterating over. There are multiple ways of going through each item of an iterator synchronously while performing an asynchronous operation, but the easiest in this case I think would be to simply use a normal for operator, which does wait for the operation to finish. const urls = [...] for (let i = 0; i < urls.length; i++) { const url = urls[i]; await page.goto(`${url}`); await page.waitForNavigation({ waitUntil: 'networkidle2' }); } This would visit one url after another, as you are expecting. If you are curious about iterating serially using await/async, you can have a peek at this answer: https://stackoverflow.com/a/24586168/791691 The accepted answer shows how to serially visit each page one at a time. However, you may want to visit multiple pages simultaneously when the task is embarrassingly pa...