create requirements.txt without virtualenv?

hi! Is there a way to create a requrirements.txt file without creating a virtualenv? I’m trying to build a series of lambdas that each have separate Pipfiles.

After cding into each lambdas fodler, I’m running pipenv lock -r | pip install -r /dev/stdin --target src. Unfortunately, it creates a virtualenv per invocation which wastes time.

Is there an easy way to just translate the Pipfile.lock -> requirements.txt format without creating the virtualenv?

Thanks!

[petergaultney]

here’s a slightly more full-featured version of @uranusjr 's workaround for this issue, which I would still love to see the pipenv maintainers reconsider.

def pipenv_lock(lockfile: str):
    """If you rely on `pipenv lock -r to do this for you, it will force-create a venv for you.
     This is a workaround that gives the same result.
    """
    from pipenv.vendor.requirementslib import Requirement
    # this is imported late because it very rudely does a basicConfig on logging
    # which will prevent basicConfig in your own scripts from taking effect
    section = 'default' if lockfile == 'requirements.txt' else 'develop'
    with open('Pipfile.lock') as f:
        with open(lockfile, 'w') as outf:
            data = json.load(f)
            for source in data.get('_meta', {}).get('sources', []):
                url = source['url']
                if source['name'] == 'pypi':
                    outf.write(f'-i {url}\n')
                else:
                    outf.write(f'--extra-index-url {url}\n')
            for name, entry in data[section].items():
                r = Requirement.from_pipfile(name, entry)
                outf.write(r.as_line() + '\n')

[AlJohri]

Why would you do that?

AWS Lambda requires a flat folder with all packages installed. I’m running the same command (pipenv lock -r | pipenv run pip install -r /dev/stdin --target src) in production on codepipeline and for local development via the aws-sam-cli.

Locally, I need to prefix pipenv run to pip install so that pip doesn’t see my globally installed packages. Otherwise, locally, I get weird issues like:

awscli 1.15.83 has requirement botocore==1.10.82, but you'll have botocore 1.11.6 which is incompatible.

In production, the virtualenv doesn’t exist so the weird parallel creation of virtualenv occurs.

Might be too much of an edgecase.