What version of Python do you use for development?

For development, I usually use Python version 3.8 or higher, as many modern language features have been introduced starting from this version, such as improved support for type annotations, new syntactic constructs, and enhancements in the standard library. Depending on the project, I may also use newer versions, such as 3.10 or 3.11, to take advantage of the latest optimizations and features.