bad message when %pylab fails due import *other* than matplotlib

[ivanov]

this is just to capture an issue that was sent to IPython-User by
@michaelaye:

I know you guys are busy getting a release on 1.0 done, so here's some
feedback trying to use git master:

In version
rel-0.13-3590-gadb77e3
matplotlib is not found, even so it is importable, so when using pylab
mode I get an error message:

Python 2.7.3 |EPD 7.3-2 (64-bit)| (default, Apr 12 2012, 11:14:05)
Type "copyright", "credits" or "license" for more information.

IPython 1.0.dev -- An enhanced Interactive Python.
? -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help -> Python's own help system.
object? -> Details about 'object', use 'object??' for extra details.

In [1]: import matplotlib

In [2]: pylab
ERROR: pylab mode doesn't work as matplotlib could not be found.
Is it installed on the system?

And since version ((rel-0.13-3681-g123ae5a)) up to now I get an import
error for the sip module (using --pylab=qt)

ImportError: No module named sip

Michael

[ivanov]

can you try using a different gui backend ( --pylab=tk for example ) .

I remember running into an issue like this one and having to set the export QT_API="pyside" or export QT_API="pyqt" depending on which version of Qt was installed...

[michaelaye]

I'm sorry, this might be due to problems on my system, brew does not install sip currently on my system, and was since corked. Sorry for the noise and let's close this for now.

[michaelaye]

yeah, --pylab=tk works fine.

[michaelaye]

as a warning to other EPD users: the config files provided in the path by the EPD path indeed blocked my brew install of sip. Had to take out EPD from the path, do brew install sip and reactivate the EPD path. Now that I have everything (=sip and pyqt updated) running again, there's no prob with IPython master. Sorry again.

[minrk]

I don't think it's pylab mode that's broken, it's that sip (PyQt) is actually at fault, but we turn any ImportError into the message you were discussing. Can you try PR #3683, which touches exactly this code, and see if it behaves better for you?

[michaelaye]

As I said, all my errors are gone since sip is back in play.

[minrk]

Sorry. I think the ImportError swallowing the real error and telling you matplotlib is unavailable is actually fixed by that PR.

[ivanov]

closing this, as Michael was able to resolve this issue