Selectively skip package from Pipfile

[lk-geimfari]

How about the feature for skipping some packages selectively, I mean something like this:

~ pipenv install --skip "mypy"

Why?

Some packages not incompatible with some implementations of Python (mypy does not work with PyPy for example) and it would be awesome to have feature for skipping such packages on installing.

For example on building on CI:

  - if [[ $TRAVIS_PYTHON_VERSION == "pypy3" ]]; then pipenv install --dev --skip "mypy"; fi

[uranusjr]

I feel PEP 508-style markers are better suited for this kind of problems. Instead of just mypy = "*", write this in the Pipfile:

mypy = { version = "*", platform_python_implementation = "=='CPython'" }

The syntax should be pretty straightforward, and there are quite some variants available. See PEP 508 for a list of available markers, and examples in Pipfile’s README for some examples.

[lk-geimfari]

@uranusjr Sounds good. I'll try it. Thank you!