Will the Event Loop switch if one of the coroutines performs a heavy CPU-bound task?

The Event Loop in Python (for example, in asyncio) will not switch if one of the coroutines performs a heavy CPU-bound task without explicitly yielding control.

This is because the Event Loop runs in a single thread and switches between tasks only when the current task yields control (for example, via await). If a coroutine performs a long synchronous operation that blocks the CPU, the Event Loop cannot switch to other tasks, leading to a 'freeze' of the asynchronous cycle.

To avoid this, heavy CPU-bound tasks are usually offloaded to separate threads or processes (for example, using concurrent.futures.ThreadPoolExecutor or ProcessPoolExecutor), or by using asynchronous libraries that do not block the Event Loop.