How to use the psyplot.project.open_dataset function in psyplot

def test_plot_creation_01_array(self):
        """Test the plot creation with a plotter that takes one array"""
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter')
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name='t2m')
        self.assertEqual(len(sp), 1)
        self.assertEqual(sp[0].name, 't2m')
        self.assertEqual(sp[0].shape, ds.t2m.shape)
        self.assertEqual(sp[0].values.tolist(), ds.t2m.values.tolist())
        psy.close()
        psy.unregister_plotter('test_plotter')

def test_figs(self):
        """Test the :attr:`psyplot.project.Project.figs` attribute"""
        psy.register_plotter('test_plotter', import_plotter=True,
                             module='test_plotter', plotter_name='TestPlotter')
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name='t2m', time=[1, 2])
        self.assertEqual(sp[0].psy.ax.figure.number, 1)
        self.assertEqual(sp[1].psy.ax.figure.number, 2)
        figs = sp.figs
        self.assertIn(sp[0].psy.ax.figure, figs)
        self.assertIs(figs[sp[0].psy.ax.figure][0], sp[0])
        self.assertIn(sp[1].psy.ax.figure, figs)
        self.assertIs(figs[sp[1].psy.ax.figure][0], sp[1])

def test_plot_creation_11_post_fmt(self):
        """Test the :attr:`psyplot.plotter.Plotter.post` formatoption"""
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter')
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        # test whether it is plotted automatically
        sp = psy.plot.test_plotter(ds, name='t2m',
                                   post='self.ax.set_title("test")')
        self.assertEqual(sp.plotters[0].ax.get_title(), 'test')
        # test whether the disabling works
        sp = psy.plot.test_plotter(ds, name='t2m', enable_post=False,
                                   post='self.ax.set_title("test")')
        self.assertEqual(sp.plotters[0].ax.get_title(), '')

def test_plot_creation_02_array_default_dims(self):
        # add a default value for the y dimension
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter',
                             default_dims={'y': 0})
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name='t2m')
        self.assertEqual(len(sp), 1)
        self.assertEqual(sp[0].name, 't2m')
        self.assertEqual(sp[0].shape, ds.t2m.isel(lat=0).shape)
        self.assertEqual(sp[0].values.tolist(),
                         ds.t2m.isel(lat=0).values.tolist())
        psy.close()
        psy.unregister_plotter('test_plotter')

def test_plot_creation_03_2arrays(self):
        # try multiple names and dimension
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter',
                             default_dims={'y': 0})
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name=['t2m', 'u'], x=slice(3, 5))
        self.assertEqual(len(sp), 2)
        self.assertEqual(sp[0].name, 't2m')
        self.assertEqual(sp[1].name, 'u')
        self.assertEqual(sp[0].shape,
                         ds.t2m.isel(lat=0, lon=slice(3, 5)).shape)
        self.assertEqual(sp[1].shape,
                         ds.u.isel(lat=0, lon=slice(3, 5)).shape)
        self.assertEqual(sp[0].values.tolist(),
                         ds.t2m.isel(lat=0, lon=slice(3, 5)).values.tolist())
        self.assertEqual(sp[1].values.tolist(),
                         ds.u.isel(lat=0, lon=slice(3, 5)).values.tolist())
        psy.close()
        psy.unregister_plotter('test_plotter')

def test_export_01_replacement(self):
        """Test exporting a project"""
        import matplotlib.pyplot as plt
        from matplotlib.testing.compare import compare_images
        import pandas as pd
        import numpy as np
        from tempfile import NamedTemporaryFile

        self._register_export_plotter()

        with psy.open_dataset(bt.get_file('test-t2m-u-v.nc')) as ds:
            time = ds.time
            time.values  # make sure the data is loaded

        ds = xr.Dataset(
            {"v0": xr.Variable(('x', 'y'), np.arange(3 * 5).reshape(3, 5)),
             "v1": xr.Variable(('time', 'y'), np.arange(5 * 5).reshape(5, 5))},
            {"x": xr.Variable(('x', ), [4, 5, 6]),
             "y": xr.Variable(('y', ), [6, 7, 8, 9, 10]),
             'time': time})
        # create reference plots
        reffiles = []
        fig, ax = plt.subplots()
        ds.v0[1].plot(ax=ax)
        reffiles.append(
            NamedTemporaryFile(prefix='psyplot_', suffix='.png').name)
        self._created_files.update(reffiles)

# test list of list with array and an array out of 2 variables
        # psyplot.project.Project([
        #     arr0: psyplot.data.InteractiveList([
        #         arr0: 3-dim DataArray of t2m, with
        #             (time, lev, lat)=(5, 4, 96), lon=1.875,
        #         arr1: 4-dim DataArray of u, v, with
        #             (variable, time, lev, lat)=(2, 5, 4, 96), lon=1.875]),
        #     arr1: psyplot.data.InteractiveList([
        #         arr0: 3-dim DataArray of t2m, with
        #             (time, lev, lat)=(5, 4, 96), lon=1.875,
        #         arr1: 4-dim DataArray of u, v, with
        #             (variable, time, lev, lat)=(2, 5, 4, 96), lon=1.875])])
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter', prefer_list=True)
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name=[['t2m', ['u', 'v']]], x=[1, 2])
        self.assertEqual(len(sp), 2)
        self.assertEqual(len(sp[0]), 2)
        self.assertEqual(len(sp[1]), 2)
        self.assertEqual(sp[0][0].name, 't2m')
        self.assertIn('variable', sp[0][1].dims)
        self.assertEqual(sp[0][1].coords['variable'].values.tolist(),
                         ['u', 'v'])
        self.assertEqual(sp[1][0].name, 't2m')
        self.assertIn('variable', sp[1][1].dims)
        self.assertEqual(sp[1][1].coords['variable'].values.tolist(),
                         ['u', 'v'])
        self.assertEqual(sp[0][0].shape, ds.t2m.isel(lon=1).shape)
        self.assertEqual(list(sp[0][1].shape),
                         [2] + list(ds.u.isel(lon=1).shape))
        self.assertEqual(sp[1][0].shape, ds.t2m.isel(lon=2).shape)

def test_plot_creation_07_list_and_dims(self):
        # use dimensions which should result in one list with 4 arrays,
        # t2m, t2m, u, u
        # psyplot.project.Project([arr3: psyplot.data.InteractiveList([
        #     arr0: 3-dim DataArray of t2m, with
        #         (time, lev, lat)=(5, 4, 96), lon=1.875,
        #     arr1: 3-dim DataArray of t2m, with
        #         (time, lev, lat)=(5, 4, 96), lon=3.75,
        #     arr2: 3-dim DataArray of u, with
        #         (time, lev, lat)=(5, 4, 96), lon=1.875,
        #     arr3: 3-dim DataArray of u, with
        #         (time, lev, lat)=(5, 4, 96), lon=3.75])])
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter', prefer_list=True)
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(ds, name=['t2m', 'u'], x=[1, 2])
        self.assertEqual(len(sp), 1)
        self.assertEqual(len(sp[0]), 4)
        self.assertEqual(sp[0][0].name, 't2m')
        self.assertEqual(sp[0][1].name, 't2m')
        self.assertEqual(sp[0][2].name, 'u')
        self.assertEqual(sp[0][3].name, 'u')
        self.assertEqual(sp[0][0].shape, ds.t2m.isel(lon=1).shape)
        self.assertEqual(sp[0][1].shape, ds.t2m.isel(lon=2).shape)
        self.assertEqual(sp[0][2].shape, ds.u.isel(lon=1).shape)
        self.assertEqual(sp[0][3].shape, ds.u.isel(lon=2).shape)
        self.assertEqual(sp[0][0].values.tolist(),
                         ds.t2m.isel(lon=1).values.tolist())
        self.assertEqual(sp[0][1].values.tolist(),
                         ds.t2m.isel(lon=2).values.tolist())
        self.assertEqual(sp[0][2].values.tolist(),

def test_save_and_load_07_sharedx(self):
        """Test whether shared x- and y-axis are restored correctly"""
        psy.register_plotter('test_plotter', import_plotter=True,
                             module='test_plotter', plotter_name='TestPlotter')
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        plt.close('all')
        fig, axes = plt.subplots(1, 3, sharex=True)
        sp = psy.plot.test_plotter(ds, name=['t2m', 'u', 'v'], x=0, y=4,
                                   ax=axes)
        axes[0].set_xlim(5, 10)
        self.assertEqual(list(axes[1].get_xlim()), [5, 10])
        # save the project
        fname = 'test.pkl'
        self._created_files.add(fname)
        sp.save_project(fname)
        psy.close('all')

        # load the project
        sp = psy.Project.load_project(fname)
        self.assertEqual(len(sp.axes), 3, msg=sp.axes)
        sp[0].psy.ax.set_xlim(10, 15)

# test list of list of arrays
        # psyplot.project.Project([
        #     arr0: psyplot.data.InteractiveList([
        #         arr0: 3-dim DataArray of t2m, with
        #             (time, lev, lat)=(5, 4, 96), lon=1.875,
        #         arr1: 3-dim DataArray of u, with #
        #             (time, lev, lat)=(5, 4, 96), lon=1.875]),
        #     arr1: psyplot.data.InteractiveList([
        #         arr0: 3-dim DataArray of t2m, with
        #             (time, lev, lat)=(5, 4, 96), lon=3.75,
        #         arr1: 3-dim DataArray of u, with
        #             (time, lev, lat)=(5, 4, 96), lon=3.75])])
        psy.register_plotter('test_plotter',
                             import_plotter=True, module='test_plotter',
                             plotter_name='TestPlotter', prefer_list=True)
        ds = psy.open_dataset(bt.get_file('test-t2m-u-v.nc'))
        sp = psy.plot.test_plotter(bt.get_file('test-t2m-u-v.nc'),
                                   name=[['t2m', 'u']], x=[1, 2])
        self.assertEqual(len(sp), 2)
        self.assertEqual(len(sp[0]), 2)
        self.assertEqual(len(sp[1]), 2)
        self.assertEqual(sp[0][0].name, 't2m')
        self.assertEqual(sp[0][1].name, 'u')
        self.assertEqual(sp[1][0].name, 't2m')
        self.assertEqual(sp[1][1].name, 'u')
        self.assertEqual(sp[0][0].shape, ds.t2m.isel(lon=1).shape)
        self.assertEqual(sp[0][1].shape, ds.u.isel(lon=1).shape)
        self.assertEqual(sp[1][0].shape, ds.t2m.isel(lon=2).shape)
        self.assertEqual(sp[1][1].shape, ds.u.isel(lon=2).shape)
        self.assertEqual(sp[0][0].values.tolist(),
                         ds.t2m.isel(lon=1).values.tolist())
        self.assertEqual(sp[0][1].values.tolist(),