How to get "python -m venv" to directly install latest pip version

I use upgrade-ensurepip to update those pip and setuptools wheel files that are part of the ensurepip package. It's not as elegant as being able to upgrade ensurepip via pip, but it's still preferable to doing it manually.

https://pypi.org/project/upgrade-ensurepip/

It is an expected behavior. python -m venv calls python -m ensurepip to install pip and This answer shows that ensurepip would only install the bundled version even with --upgrade option. There isn't any official option to update the bundled pip and setuptools.

Well I have also no good idea to fix this problem as it just is the designed behavior. I would like to give two suggestions:

1. Use pipenv. It is really good! And it will be the next-generation official package manager in the future(Although there is a big problem related to current Pypi's structure. In short, a package manager can only decide the dependencies with downloading the whole package. This gives a huge difficulty to building dependencies graph.).

2. Implement your custom EnvBuilder, actually there is an official example about this. And in the example, it also use get-pip.py to install the latest pip.

The trick is not to install the bundled version of pip (which will almost always be out of date), but to use it to install the most current version from the internet.

Standard library venv offers a --without-pip flag that can help here. After creating the virtual environment without pip, you can then you can "execute" ensurepip's wheel directly thanks to Python's zip importer. This is both faster and less hacky than installing pip and then immediately using that same pip installation to uninstall itself and upgrade.

Code speaks louder than words, so here's an example bash function for the process I've described:

# in ~/.bashrc or wherever

function ve() {
    local py="python3"
    if [ ! -d ./.venv ]; then
        echo "creating venv..."
        if ! $py -m venv .venv --prompt=$(basename $PWD) --without-pip; then
            echo "ERROR: Problem creating venv" >&2
            return 1
        else
            local whl=$($py -c "import pathlib, ensurepip; whl = list(pathlib.Path(ensurepip.__path__[0]).glob('_bundled/pip*.whl'))[0]; print(whl)")
            echo "boostrapping pip using $whl"
            .venv/bin/python $whl/pip install --upgrade pip setuptools wheel
            source .venv/bin/activate
        fi
    else
        source .venv/bin/activate
    fi
}

If you prefer the older project virtualenv, it also offers --no-pip, --no-setuptools, and --no-wheel flags to achieve the same on Python 2.7.

Note: Python 3.9+ venv has an --upgrade-deps option to immediately upgrade the pip/setuptools versions after creating an environment, see https://bugs.python.org/issue34556 for more info about that. I don't use this option because it still goes through an unnecessary install/uninstall of the vendored versions, which is inferior to the method of creating an environment with the latest versions directly as shown above.