Convert virtualenv instance/`requirements.txt` to pipenv

Question

I've got a lot of projects using the virtualenv and requirements.txt or ./requirements/ pattern, but now using pipenv is obviously many times superior.

It seems to be easy to generate requirements.txt from pipenv, but going the other way seems more confusing.

There doesn't seem to be an obvious way to "convert" existing projects to pipenv.

I'm writing a script to execute pipenv on everything in a large requirements.txt but this can't be right -- is there a way to apply an existing requirements.txt to a pipenv?

Answer 1

OK, I figured out to answer my own question and think there's potential for an "official"/detailed way of doing this:

$ pipenv shell
(env) $ pip install -r requirements

Also this exists now: https://pipenv.kennethreitz.org/en/latest/basics/#importing-from-requirements-txt

$ pipenv install -r path/to/requirements.txt

Really I'd just misunderstood the levels of abstraction of pipenv.