What is grequests?

GRequests is a Python library that lets you send many web requests at the same time instead of one at a time. Normally, when a Python program fetches a web page or calls an API, it waits for the response before moving on to the next request. If you need to fetch 50 URLs, you wait for the first one to finish, then the second, and so on. GRequests changes this by using a library called Gevent to fire off all the requests at once and collect the results when they are ready. The interface mirrors the popular Requests library closely, so anyone already familiar with how Requests works can switch to GRequests with minimal changes. Instead of calling requests.get() directly, you create a list of request objects and pass them to grequests.map(), which sends them all simultaneously and returns a list of responses in the same order as the inputs. Failed requests return None in the results list, and you can supply an optional error handler function that runs whenever a request fails. For cases where you want to process responses as they arrive rather than waiting for all of them, the library provides an imap() function that returns a generator. Responses come back in whatever order they finish, not the order they were sent, which can be faster for large batches. An enumerated version of imap is also available if you need to know which original request each response corresponds to. One practical note in the README: because Gevent works by patching Python's standard networking code at startup, GRequests should be imported before the Requests library in your code, or you may encounter subtle concurrency bugs. Installation is via pip and the package is available on PyPI.