Are streams in Python native?

No, threads in Python (threading) are not fully native. They are implemented on top of the native threads of the operating system, but due to the Global Interpreter Lock (GIL), only one thread can execute Python bytecode at a time.

The GIL is a mutex that protects access to Python objects, preventing multiple native Python threads from executing Python bytecode simultaneously. This simplifies memory management but limits true parallelism on multi-core processors for CPU-bound tasks.

However, for I/O-bound tasks (networking, file operations, etc.), threads can be useful because the GIL is released during I/O waits, allowing other threads to run.

To achieve true parallelism for CPU-bound tasks in Python, multiprocessing (processes) is used, which runs in separate Python interpreters and does not share the GIL.