ipython notebook, matplotlib und der ItalicAngle-Fehler

Heute wollte ich das erste Mal das bei uns auf den Uni-Rechnern installierte ipython notebook testen.

Zu meinem Erstaunen stürzte es bei mir schon während des Starts mit einer Fehlermeldung ab:

    Value error parsing header in AFM: ItalicAngle -9,9
    Traceback (most recent call last):
    File "/usr/bin/ipython", line 8, in <module>
        launch_new_instance()
    File "/usr/lib/python2.7/dist-packages/IPython/frontend/terminal/ipapp.py", line 388, in launch_new_instance
        app.initialize()
    File "<string>", line 2, in initialize
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 84, in catch_config_error
        return method(app, *args, **kwargs)
    File "/usr/lib/python2.7/dist-packages/IPython/frontend/terminal/ipapp.py", line 313, in initialize
        super(TerminalIPythonApp, self).initialize(argv)
    File "<string>", line 2, in initialize
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 84, in catch_config_error
        return method(app, *args, **kwargs)
    File "/usr/lib/python2.7/dist-packages/IPython/core/application.py", line 325, in initialize
        self.parse_command_line(argv)
    File "/usr/lib/python2.7/dist-packages/IPython/frontend/terminal/ipapp.py", line 308, in parse_command_line
        return super(TerminalIPythonApp, self).parse_command_line(argv)
    File "<string>", line 2, in parse_command_line
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 84, in catch_config_error
        return method(app, *args, **kwargs)
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 420, in parse_command_line
        return self.initialize_subcommand(subc, subargv)
    File "<string>", line 2, in initialize_subcommand
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 84, in catch_config_error
        return method(app, *args, **kwargs)
    File "/usr/lib/python2.7/dist-packages/IPython/config/application.py", line 352, in initialize_subcommand
        subapp = import_item(subapp)
    File "/usr/lib/python2.7/dist-packages/IPython/utils/importstring.py", line 40, in import_item
        module = __import__(package,fromlist=[obj])
    File "/usr/lib/python2.7/dist-packages/IPython/frontend/html/notebook/notebookapp.py", line 59, in <module>
        from IPython.frontend.consoleapp import IPythonConsoleApp
    File "/usr/lib/python2.7/dist-packages/IPython/frontend/consoleapp.py", line 114, in <module>
        from IPython.zmq.pylab.backend_inline import InlineBackend
    File "/usr/lib/python2.7/dist-packages/IPython/zmq/pylab/backend_inline.py", line 13, in <module>
        from matplotlib.backends.backend_agg import new_figure_manager, FigureCanvasAgg
    File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_agg.py", line 28, in <module>
        from matplotlib.backend_bases import RendererBase,\
    File "/usr/lib/pymodules/python2.7/matplotlib/backend_bases.py", line 38, in <module>
        import matplotlib.widgets as widgets
    File "/usr/lib/pymodules/python2.7/matplotlib/widgets.py", line 16, in <module>
        from lines import Line2D
    File "/usr/lib/pymodules/python2.7/matplotlib/lines.py", line 23, in <module>
        from matplotlib.font_manager import FontProperties
    File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 1325, in <module>
        _rebuild()
    File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 1275, in _rebuild
        fontManager = FontManager()
    File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 999, in __init__
        self.afmlist = createFontList(self.afmfiles, fontext='afm')
    File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 567, in createFontList
        prop = afmFontProperty(fpath, font)
    File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 484, in afmFontProperty
        if font.get_angle() != 0 or name.lower().find('italic') >= 0:
    File "/usr/lib/pymodules/python2.7/matplotlib/afm.py", line 468, in get_angle
        return self._header['ItalicAngle']
    KeyError: 'ItalicAngle'

Interessanterweise funktionierte es bei anderen Nutzern am gleichen Rechner. Nach viel Gesuche fand sich die Lösung: in meinem Home-Ordner fehlte die Datei .matplotlib/fontList.cache ...