BLD: Install dependencies if cannot be imported.

[jseabold]

Should provide a middle ground for #169, #277, #285.

These are the same changes that were made to statsmodels in statsmodels/statsmodels#1902

I feel partially responsible for the bombardment of unhelpful/semi-rude issues you've had to field.

[mwaskom]

Ah, clever!

[mwaskom]

Thanks!

[jseabold]

@mwaskom Did you test this? I could have sworn it worked for me yesterday on a clean install, but I'm having issues now.

[mwaskom]

Heh, I did not, it looked very straightforward! :/

On Thu, Sep 25, 2014 at 1:19 PM, Skipper Seabold notifications@github.com
wrote:

@mwaskom https://github.com/mwaskom Did you test this? I could have
sworn it worked for me yesterday on a clean install, but I'm having issues
now.

—
Reply to this email directly or view it on GitHub
#300 (comment).

[mwaskom]

Hm, can confirm that it seems not to work properly, though.

[mwaskom]

I think it has something to do with the existence of the local seaborn.egg-info/ directory.

[jseabold]

That would make sense. I don't think I tried it from a source distribution only from a clean checkout.

[jseabold]

Yeah, I have no idea what's going on here but don't want to dig into it. Indeed, if your source distribution has an .egg-info file, then pip finds it and ignores the requires.txt (which may be incorrect, anyway, if you build the sdist in an environment that has the dependencies). We formerly had a custom sdist command that didn't add the egg-info. Now I'm just going to exclude it using MANIFEST.in. Will let you know if I get to the bottom of it.

[jseabold]

Unfortunately, it doesn't look like removing the egg-info from the sdist has any effect.

[jseabold]

Ok easy fix actually. You can just remove the the sys.argv check. Worst case, you don't have those packages, no error is raised, they're installed by pip. Best case, they're found. No pip upgrade behavior. I think that's right...

[mwaskom]

Ah, because we won't get ImportErrors raised anymore so things like pip install pandas seaborn should still work?

[jseabold]

I'll have to check that for sure. But, yes, I think it would work here. Never raises an error and adds to installation list if it needs to.

For future reference for people who want to complain. Here's the 3 year old bug report for pip on the recursive upgrade behavior being a bug and their devs stating it's a bug [1]. Hopefully, we can at least get some traction from this soon [2].

[1] pypa/pip#304
[2] pypa/pip#59

[mwaskom]

OK see #306 for what I think is a solution.

[jseabold]

Looks right to me.