Learn Python by Building Data Science Applications

Different types of concurrency

There are various ways to achieve concurrency in Python, including threads, tasks, processes, and so on. First, while we say that a concurrent task occurs simultaneously, this is not always the case. In fact, threads and tasks don't really run concurrently—instead, the CPU can switch between different threads really fast so that they seem to be running in parallel, but it always executes one thread at a time. This is ensured by part of the Python interpreter called Global Interpreter Lock, or GIL. Threading can still boost your code execution, which it does by switching to other threads when the CPU is waiting for data to be loaded from the network—we'll talk about that in a minute.

Even then, there are multiple ...