Why does Python Not Support Multithreading?

Python is an extremely famous programming language utilized for a wide variety of applications. Despite its several benefits, it suffers from a drawback: it lacks native assistance for multithreading. As a result, developers who intend to write concurrent code in Python ought to count on workarounds or third-party libraries. In this article, we will delve into the motives behind Python's incapability to guide multithreading and discuss a range of preferences that builders can make use of to ignore this limitation.

What is Multithreading?

Understanding what multithreading is and how it works is critical earlier than we can recognize why Python would not guide it.

Multithreading, in its simplest form, is an approach for carrying out many threads of operation simultaneously. Each thread operates independently from the others and has the capacity to run unique sections of the software program simultaneously. In conditions where a number of tasks can be carried out simultaneously, this approach is especially advisable for enhancing the overall performance and responsiveness of programs.

Reasons for Python's Lack of Support for Multithreading?

Python's lack of multithreading instruction is due to the Global Interpreter Lock (GIL). The GIL is a mechanism that guarantees only one thread can execute Python bytecode at a time. Essentially, it implies that even though numerous threads can exist in a Python process, they are incapable of executing Python code concurrently. This is because the GIL restricts the interpreter to a single thread, which prevents other threads from executing Python code.

The Global Interpreter Lock exists because Python adopts a reference-counting memory management model, which deletes objects when their reference count reaches zero. The GIL guarantees that the reference count is accurate, even when multiple threads are simultaneously accessing the same object. If the GIL were not in place, there would be race conditions whereby two threads may attempt to modify the reference count of the same object concurrently, resulting in memory corruption.

The fact that many applications now do not require multithreading makes Python's lack of support for it in part understandable. Python used to be designed to be a high-level, user-friendly, and readable language. Python lacks many intricate and low-level elements seen in other programming languages as a result. Although it is a powerful tool, multithreading is now not required for all Python applications. The single-threaded Python paradigm typically serves the meaning well.

Python Libraries

Although Python no longer has built-in help for multithreading, there are nonetheless numerous workarounds and third-party libraries that can be used to achieve concurrency. The threading module is an ordinary library that presents an approach for jogging more than one thread in a Python process. However, the threading module can solely provide concurrency for I/O-bound tasks, such as community verbal exchange or disk I/O, due to the GIL. It can't grant concurrency for CPU-bound tasks, such as mathematical computations.

The multiprocessing module is another popular library used for concurrency in Python. It enables running multiple Python processes within a single application. Unlike the threading module, each process within multiprocessing has its own interpreter and memory space, which exempts it from the GIL. This characteristic makes the multiprocessing module appropriate for both CPU-bound tasks and I/O-bound tasks.


In summary, Python lacks a native guide for multithreading due to the fact of the Global Interpreter Lock, which is essential to hold the accuracy of reference counting in Python's memory management model. Furthermore, Python prioritizes its high-level and simple design, and thus, multithreading is no longer constantly required for many applications. Nonetheless, there are more than one workaround and third-party libraries, like the threading and multiprocessing modules, handy to obtain concurrency in Python. It is integral for builders to know the boundaries of these libraries and decide on the one that suits their application's unique needs.

Updated on: 04-Apr-2023


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