Will Python 4 Be Backward‑Compatible? Guido’s Take on the Next Release

Discussion on Python 4

Hello, I’m “菜鸟哥” and today we explore the topic of Python 4.

Since January 1 2020 the official support for Python 2 ended, and Python 3 became the standard. As time passes, speculation about a future Python 4 release has grown.

Recently, while browsing an overseas forum, I saw questions about Python 4 that were answered by Python’s creator, Guido van Rossum (referred to as “龟叔”). Here are the key points he made:

After Python 3.9 the next version is Python 3.10, which is still part of the Python 3 series and already exists on GitHub.

If a Python 4 appears, its transition would resemble the shift from Python 1 to Python 2 rather than the disruptive change from Python 2 to Python 3.

Python 1 was released in January 1994, while Python 2 arrived in October 2000. The move from 1 to 2 was backward‑compatible, meaning Python 2 could run Python 1 code. In contrast, the Python 2‑to‑3 migration suffered severe compatibility issues, prompting the creation of the 2to3 conversion tool.

Guido’s implication is that Python 4 should be compatible with Python 3.

Current community sentiment shows limited hype for Python 4; most users are watching and hoping for substantial improvements. Many expect that without notable performance gains or architectural changes, the language will retain the “Python 3” naming convention rather than jump to “Python 4”.

Comments from readers express a desire for a smooth transition, avoiding the “dual‑version” confusion that occurred between Python 2 and Python 3.

From my perspective, a successful Python 3‑to‑4 upgrade would require major enhancements such as just‑in‑time (JIT) compilation to mitigate the Global Interpreter Lock (GIL) bottleneck and boost execution speed.

In summary, whether Python 4 is released this year or later, its arrival seems inevitable. The community’s expectations revolve around compatibility with Python 3 and significant performance improvements.