| Concurrency Type | Switching Decision | Number of Processors |
|---|---|---|
| Pre-emptive multitasking (threading) | The operating system decides when to switch tasks external to Python. | 1 |
| Cooperative multitasking (asyncio) | The tasks decide when to give up control. | 1 |
| Multiprocessing (multiprocessing) | The processes all run at the same time on different processors. | Many |
Adding concurrency to your program adds extra code and complications, so you’ll need to decide if the potential speed up is worth the extra effort.
| I/O-Bound Process | CPU-Bound Process |
|---|---|
| Your program spends most of its time talking to a slow device, like a network connection, a hard drive, or a printer. | You program spends most of its time doing CPU operations. |
| Speeding it up involves overlapping the times spent waiting for these devices. | Speeding it up involves finding ways to do more computations in the same amount of time. |