flag to force use of --find-links and ignore later PyPI versions

[blink1073]

Presumably, if the user specifies --find-links, they would prefer to install packages from that directory versus PyPI. For example, if I have a wheelhouse with matplotlib, and I specify pip install -f $WHEELHOUSE matplotlib, it should install from there. However, it will default to install from PyPI unless I ALSO specify --no-index.
You might say that this is the desired behaviour. However, what if I have a requirements.txt file and some of the packages are hosted in my wheelhouse and the others are available on PyPI? There is no pip command that will allow me to install my packages using the requirements.txt file, unless I am missing something.

[pfmoore]

Can you give a specific example? I believe the case you mentioned works as expected - any distributions available via PyPI and --find-links are taken together and the newest version that satisfies the requirements is selected. Does PyPI have a later version of matplotlib than your wheelhouse? If so, then PyPI will be preferred for that reason. You will need to specify the version if you want to avoid getting newer versions from PyPI.

If the issue is that you need a binary wheel and the PyPI distribution is source-only, then #2084 may be relevant to you. At present, there's no way to say to pip "only consider wheels", so a newer source-only distribution on PyPI will be preferred to an older wheel.

[blink1073]

For example, scikit-image requires matplotlib>=1.1.0. It also supports Py3.2, but matplotlib no longer supports Py3.2 as of 1.4.0. If I have a wheel in my wheelhouse that satisfies the requirement, I'd prefer to use that over the PyPI version.
Perhaps we need another command line option that does what we'd like?

[blink1073]

Otherwise, we need to make sure ALL of the required dependencies are hosted on that site, even if they can just as easily be gotten from PyPI (e.g. tifffile).

[blink1073]

How about --preferred-link?

[piotr-dobrogost]

There is no pip command that will allow me to install my packages using the requirements.txt file, unless I am missing something.

I'm afraid you're not missing anything :/ The problem is there's no way to specify per requirement pip options besides --editable in requirements file. If there were such an option then you could specify --no-index and --find-links for packages that you want to be installed from your wheelhouse. Btw, documentation on Package Index Options supported in requirements file is unclear; it doesn't say that these options are global to all requirements in requirements file. Also there's no information in the docs on if and how the options from command line are being merged with options given in requirements file.

Presumably, if the user specifies --find-links, they would prefer to install packages from that directory versus PyPI.

This would indeed solve your problem but I have an impression the root problem is what I described above as you are specifically concerned with using requirements file and there is already a combination of pip options – --no-index and --find-links – that would work if it were supported per requirement in requirements file.

You might take a look at #271 which is concerned with adding some options per requirement. There you will find #271 (comment) with a link to SO question with workaround (using shell script and invoking pip for every requirement).

[msabramo]

Could you put in your requirements:

matplotlib>=1.1.0,<1.4.0

?

Then it would hopefully prefer your local wheel for matplotlib and get the rest from PyPI, no?

[blink1073]

What I ended up doing is editing the requirements.txt file for that one build to use matplotlib==1.1.0 instead of matplotlib>=1.1.0. We don't want to necessarily put an upper limit on the MPL version.

[msabramo]

So I wonder if a pip change is still desired or if it's not needed since you were able to get things working?

[blink1073]

I would call what I did a hack, and still advocate for a built in solution.

[piotr-dobrogost]

What I ended up doing is editing the requirements.txt file for that one build to use matplotlib==1.1.0 instead of matplotlib>=1.1.0. We don't want to necessarily put an upper limit on the MPL version.

How does it help?

[blink1073]

It is working for us. We have a Travis build specifically against minimum dependencies, and we just replace all the >= in our requirements file with ==.

[Themanwithoutaplan]

I need this to be able to point to local Windows binaries (of lxml but it could be anything) that aren't available online. Behaviour would be to check the local folder first and only going online if something was missing from it. This would allow configuration using pip.ini which reduces typos and explaining this to users (an welcome hurdle when working with newbies on Windows).