version - Upgrade python in a virtualenv

Question

Is there a way to upgrade the version of python used in a virtualenv (e.g. if a bugfix release comes out)?

I could pip freeze --local > requirements.txt, then remove the directory and pip install -r requirements.txt, but this requires a lot of reinstallation of large libraries, for instance, numpy, which I use a lot.

I can see this is an advantage when upgrading from, e.g., 2.6 -> 2.7, but what about 2.7.x -> 2.7.y?

Answer 1

If you happen to be using the venv module that comes with Python 3.3+, it supports an --upgrade option. Per the docs:

Upgrade the environment directory to use this version of Python, assuming Python has been upgraded in-place

python3 -m venv --upgrade ENV_DIR