Launching IPython qtconsole from command line (after installing all dependencies)

Question

I am a bit of a newbie to the command line. I used to have IPython (with all dependencies configured) on my last MacBook, such that I could click on an icon from the dash to launch iPython qtconsole (outside of terminal shell).

Now, on my new MacBook Pro, after installing all of the same files and dependencies, I am getting:

Jacobs-MacBook-Pro:~ Jacob$ ipython qtconsole
Traceback (most recent call last):
  File "/usr/local/bin/ipython", line 8, in <module>
    load_entry_point('ipython==1.0.dev', 'console_scripts', 'ipython')()
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/frontend/terminal/ipapp.py", line 390, in launch_new_instance
    app.initialize()
  File "<string>", line 2, in initialize
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/frontend/terminal/ipapp.py", line 315, in initialize
    super(TerminalIPythonApp, self).initialize(argv)
  File "<string>", line 2, in initialize
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/core/application.py", line 323, in initialize
    self.parse_command_line(argv)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/frontend/terminal/ipapp.py", line 310, in parse_command_line
    return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "<string>", line 2, in parse_command_line
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 429, in parse_command_line
    return self.initialize_subcommand(subc, subargv)
  File "<string>", line 2, in initialize_subcommand
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 84, in catch_config_error
    return method(app, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/config/application.py", line 361, in initialize_subcommand
    subapp = import_item(subapp)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/utils/importstring.py", line 40, in import_item
    module = __import__(package,fromlist=[obj])
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/frontend/qt/console/qtconsoleapp.py", line 56, in <module>
    from IPython.external.qt import QtCore, QtGui
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/external/qt.py", line 23, in <module>
    QtCore, QtGui, QtSvg, QT_API = load_qt(api_opts)
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/external/qt_loaders.py", line 241, in load_qt
    result = loaders[api]()
  File "/Library/Python/2.7/site-packages/ipython-1.0.dev-py2.7.egg/IPython/external/qt_loaders.py", line 171, in import_pyqt4
    from PyQt4 import QtGui, QtCore, QtSvg
ImportError: dlopen(/Library/Python/2.7/site-packages/PyQt4/QtGui.so, 2): Library not loaded: /usr/local/lib/QtGui.framework/Versions/4/QtGui
  Referenced from: /Library/Python/2.7/site-packages/PyQt4/QtGui.so
  Reason: image not found

and, again being a newbie, I think part of the problem may rely on the output, here:

Jacobs-MacBook-Pro:~ Jacob$ brew install qt
Warning: It appears you have MacPorts or Fink installed.
Software installed with other package managers causes known problems for
Homebrew. If a formula fails to build, uninstall MacPorts/Fink and try again.
Warning: qt-4.8.4 already installed, it's just not linked

Thanks in an advance for any tips. And if you need me to run any command (to view more outputs) just let me know!

I have *never* had any luck getting python to build with Qt bindings on mac or ubuntu. One option is to try using a python distribution that has pre-compiled support for Qt, like Enthought Canopy (https://www.enthought.com/products/canopy/) .or Anaconda (https://store.continuum.io/cshop/anaconda/) — Robert T. McGibbon, May 15 '13 at 01:37
Are you using Apple's pre-installed Python 2.7, the installer from python.org, a Homebrew package, or something else? Do you actually have MacPorts or Fink installed alongside Homebrew? How did you install Qt, PyQt (or PySide?), and ipython? If you have multiple versions of anything (and remember, if you installed _any_ Python, you do, because Apple already gave you one), what does your `PATH` look like? — abarnert, May 15 '13 at 01:38
@RobertMcGibbon: With just the Python 2.7.2 that came with OS X 10.8 (no third-party installs), `brew install pyside` worked for me out of the box. I've also had it work with Homebrew's Python. But not with python.org, or any other Python besides those two. (I've also used MacPorts python/qt/pyqt4 together with no problem, upgrading from 10.4 through 10.7 over the years. It's really only when you start installing multiple Pythons that all want to claim a piece of /usr/local that things get confusing…) — abarnert, May 15 '13 at 01:41
Point noted, @abarnert. My experience is from compiling a new version from source, and trying to get it to link against the gui backends. — Robert T. McGibbon, May 15 '13 at 01:45
in terminal: 'which python' /usr/bin/python when I launch iPython (terminal, using: ipython --pylab=inline): 'Python 2.7.2... # printed in header' — Jacob Irwin, May 15 '13 at 04:28
I did install MacPorts, and was properly using 'port install foo', but then tried to install source packages for yum (later realized how pointless this was), which caused my MacPorts to not work any longer (any of your thoughts/ideas on this would be an added bonus). ... so, now 'port install bar' fails, with output: '-bash: port: command not found' — Jacob Irwin, May 15 '13 at 04:31
@abarnert 's follow-up comment to Robert McGibbon may be exactly the issue... on my previous 2011 MacBook Pro, I had this whole thing working nicely. But maybe I installed additional Python versions when I added all my old files from an external harddrive (backup from last Mac to this new Mac). — Jacob Irwin, May 15 '13 at 04:35

score 2 · Answer 1 · answered May 15 '13 at 22:30

So, you have multiple Python installations, and aren't sure which one you have.

You have both Homebrew and MacPorts.

Your MacPorts is broken and you don't know how to fix it.

Fixing each of these may not be that hard, but I think it's time to wipe the slate clean and start over.

The "easy" way to do this is to reinstall the OS, using the standard backup-and-migrate stuff to preserve your Aqua-level apps, user preferences, documents, etc. But that's pretty drastic, and shouldn't be necessary.

To clean things up manually, first:

Uninstall MacPorts.
brew uninstall $(brew list). This removes all Homebrew packages. You could just unlink instead of uninstall, but you really want to rebuild them once your machine is cleaned up.
sudo rm -rf /Library/Python /Library/Frameworks/Python.framework /usr/local/share/python*. This wipes out most third-party Python installations. And if you don't know where yours came from, it's really the best you can do.

Take a look at whatever's left in /usr/local/bin. All kinds of stuff can end up here, from scripts installed with Apple's Python to the command-line tools for GUI apps like TextMate, Aquamacs, or GitHub to the tools that come with binary installs of SDL or Qt, so you may not want to just wipe out the whole thing—but you do want to look it all over. Also look at /usr/local/lib and /Library/Frameworks.

You also may need to edit your ~/.profile, etc. files to undo changes you or those installers may have made, like adding /opt/local/bin or /Library/Frameworks/Python.framework/Versions/2.7/bin to your PATH. There could also be changes in /etc, but that's less likely (and less likely to cause problems).

Now run brew doctor to make sure Homebrew is happy, reinstall any non-Python-related Homebrew packages and binary installers you want, and now you're ready to install/configure your python, PyQt4-or-PySide, iPython, etc. properly and live happily every after (until you buy a new computer next year).

I am going to sleep on the rebuild -- nonetheless, you really laid it out plain and simple. I appreciate it, as when I finally work up the courage to go for it, it'll be less of a hassle. Thank you. — Jacob Irwin, May 25 '13 at 07:42

Launching IPython qtconsole from command line (after installing all dependencies)

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