.python Version Jun 2026

What you are using (Windows, macOS, Linux). If you are using a manager like pyenv , conda , or uv . The exact error message you're seeing. What's New In Python 3.13 — Python 3.14.4 documentation

If a teammate updates the .python-version file in repository control, and your terminal throws an error stating that the version is not found, your local setup is missing that specific compilation build. Resolve this by downloading the target interpreter via your version manager: pyenv install $(cat .python-version) Use code with caution.

Python has evolved significantly over the years, with each version introducing new features, enhancements, and improvements. Understanding the different Python versions and their notable features can help you make informed decisions when choosing a version for your project. By selecting the right version, you can ensure that your project is compatible, maintainable, and well-supported. .python version

: If a directory doesn't have the file, the tool searches "up" the folder tree until it finds one or falls back to a global default. Setting Up Your Environment

At the same time, the Python core team is exploring ways to make version management less painful. PEP 668 (externally managed environments) is already forcing Linux distributions to be more careful about system Python modifications. What you are using (Windows, macOS, Linux)

Place a .python-version file in each subproject's root. Tools that climb the directory tree will find the correct one.

Note: Heroku requires the python- prefix on the version string. What's New In Python 3

Implementing this standard provides significant advantages across development pipelines:

# Create a virtual environment using your CURRENT Python version python3.11 -m venv .venv-311 python3.13 -m venv .venv-313

You can create this file manually or generate it automatically using a CLI tool. Method 1: Manually via Terminal Navigate to your project root and run: echo "3.12.2" > .python-version Use code with caution. Method 2: Automatically via Version Managers