non-python kernels run python code with qtconsole

[sn6uv]

When launching the qtconsole with a non-python kernel it crashes immediately since the frontend requests that the following code is run by the kernel:

try:
    _usage
except:
    from IPython.core import usage as _usage
    get_ipython().register_magic_function(_usage.page_guiref, 'line', 'guiref')
    del _usage

obviously only python kernels understand and can execute this.

Either we

• check the language of the kernel first (with a kernel_info_request message).
• find another way to register the magic functions for python kernels.

[minrk]

I think following a kernel_info request is a good idea.

[minrk]

Thanks! When you turn an Issue into a PR, it's probably a good idea to ping with a comment, because just turning it into a PR doesn't seem to cause any notification.

[sn6uv]

This might be a potential problem. i.e. if the kernel doesn't implement the language field this could crash with KeyError.

[minrk]

arg, good point. Better to be safe here.