Allow installing `provides_extras` from local wheel file

[johnthagen]

What's the problem this feature will solve?

Would like pip install mypackage-0.1.0-py3-none-any.whl to be able to optionally install the provides_extras metadata present within the wheel.

Describe the solution you'd like

Consider a package that contains the following in its setup.py:

    setup(
        ...
        extras_require={
            "encryption": ["tinyaes"],
        },

Building a bdist_wheel, we can see that this information is persisted into the wheel using pkginfo:

% pkginfo mypackage-0.1.0-py3-none-any.whl
...
provides_extras: ['encryption']

Distributing the .whl file to users is a convenient way to distribute the packaged application. It would be helpful if pip allowed for installing the provides_extras like is possible if the wheel were published to PyPI. The normal [encryption] prefix syntax does not work because pip is expecting a file path.

$ pip install --with-extras=encryption mypackage-0.1.0-py3-none-any.whl

Alternative Solutions

pip could try to re-use the same magic syntax and strip [...] from the end of file names.

$ pip install mypackage-0.1.0-py3-none-any.whl[encryption]

[pradyunsg]

The following should work: pip install 'mypackage[encryption] @ mypackage-0.1.0-py3-none-any.whl'.

[johnthagen]

I'm getting:

ERROR: Invalid requirement: 'mypackage @ mypackage-0.1.0-py3-none-any.whl'

Python 3.9.1, pip 21.0.1 / macOS.

I will see if I can create a full minimal example.

This happens with and without the [encryption].

[johnthagen]

Here is a minimal setup.py:

from setuptools import setup

setup(
    name='myproject',
    version='0.1.0',
    packages=[
        "myproject",
    ],
    install_requires=[
        'exitstatus',
    ],
    extras_require={
        "encryption": ["tinyaes"],
    },
)

(venv) $ pip list
Package    Version
---------- -------
pip        21.0.1
pkginfo    1.7.0
setuptools 54.1.0
wheel      0.36.2

(venv) $ python setup.py bdist_wheel

(venv) $ pkginfo dist/myproject-0.1.0-py3-none-any.whl 
metadata_version: 2.1
name: myproject
version: 0.1.0
platforms: ['UNKNOWN']
description: UNKNOWN



requires_dist: ['exitstatus', "tinyaes ; extra == 'encryption'"]
provides_extras: ['encryption']

(venv) $ cd dist
(venv) $ pip install 'myproject[encryption] @ myproject-0.1.0-py3-none-any.whl'
ERROR: Invalid requirement: 'myproject[encryption] @ myproject-0.1.0-py3-none-any.whl'

[pradyunsg]

Maybe mypackage @ ./<wheel>?

[pradyunsg]

Wait, pip install 'dist/package-0.1-py3-none-any.whl[extra]' works.

❯ pip install 'dist/package-0.1-py3-none-any.whl[extra]'
Processing ./dist/package-0.1-py3-none-any.whl
WARNING: package 0.1 does not provide the extra 'extra'
Installing collected packages: package
Successfully installed package-0.1

[johnthagen]

Ah, you're right. I needed the ' ' around the argument or else I got a shell error:

$ pip install myproject-0.1.0-py3-none-any.whl[encryption]  
zsh: no matches found: myproject-0.1.0-py3-none-any.whl[encryption]

$ pip install 'myproject-0.1.0-py3-none-any.whl[encryption]'
Processing ./myproject-0.1.0-py3-none-any.whl
Collecting exitstatus
  Using cached exitstatus-2.1.0-py3-none-any.whl (3.3 kB)
Collecting tinyaes
  Using cached tinyaes-1.0.1-cp39-cp39-macosx_10_15_x86_64.whl
Installing collected packages: exitstatus, tinyaes, myproject
Successfully installed exitstatus-2.1.0 myproject-0.1.0 tinyaes-1.0.1

Cool! Is this documented anywhere? Would you accept a PR to document it? I'd be willing to take a stab if you were able to point me to where you think this should be documented.

[johnthagen]

(Also, this is off topic but your furo Sphinx theme is awesome! Thanks for publishing it. ❤️ )

[pradyunsg]

I imagine a .. warning admonition somewhere in the user guide would be best?