pylabtools.py 文件源码

def find_gui_and_backend(gui=None, gui_select=None):
    """Given a gui string return the gui and mpl backend.

    Parameters
    ----------
    gui : str
        Can be one of ('tk','gtk','wx','qt','qt4','inline').
    gui_select : str
        Can be one of ('tk','gtk','wx','qt','qt4','inline').
        This is any gui already selected by the shell.

    Returns
    -------
    A tuple of (gui, backend) where backend is one of ('TkAgg','GTKAgg',
    'WXAgg','Qt4Agg','module://ipykernel.pylab.backend_inline').
    """

    import matplotlib

    if gui and gui != 'auto':
        # select backend based on requested gui
        backend = backends[gui]
    else:
        # We need to read the backend from the original data structure, *not*
        # from mpl.rcParams, since a prior invocation of %matplotlib may have
        # overwritten that.
        # WARNING: this assumes matplotlib 1.1 or newer!!
        backend = matplotlib.rcParamsOrig['backend']
        # In this case, we need to find what the appropriate gui selection call
        # should be for IPython, so we can activate inputhook accordingly
        gui = backend2gui.get(backend, None)

        # If we have already had a gui active, we need it and inline are the
        # ones allowed.
        if gui_select and gui != gui_select:
            gui = gui_select
            backend = backends[gui]

    return gui, backend