Show `rows` result of predictions on `ds_type` dataset.

def show_results(self, ds_type=DatasetType.Valid, rows:int=5, max_len:int=20):
        from IPython.display import display, HTML
        "Show `rows` result of predictions on `ds_type` dataset."
        ds = self.dl(ds_type).dataset
        x,y = self.data.one_batch(ds_type, detach=False, denorm=False)
        preds = self.pred_batch(batch=(x,y))
        y = y.view(*x.size())
        z = preds.view(*x.size(),-1).argmax(dim=2)
        xs = [ds.x.reconstruct(grab_idx(x, i)) for i in range(rows)]
        ys = [ds.x.reconstruct(grab_idx(y, i)) for i in range(rows)]
        zs = [ds.x.reconstruct(grab_idx(z, i)) for i in range(rows)]
        items,names = [],['text', 'target', 'pred']
        for i, (x,y,z) in enumerate(zip(xs,ys,zs)):
            txt_x = ' '.join(x.text.split(' ')[:max_len])
            txt_y = ' '.join(y.text.split(' ')[max_len-1:2*max_len-1])
            txt_z = ' '.join(z.text.split(' ')[max_len-1:2*max_len-1])
            items.append([txt_x, txt_y, txt_z])
        items = np.array(items)
        df = pd.DataFrame({n:items[:,i] for i,n in enumerate(names)}, columns=names)
        with pd.option_context('display.max_colwidth', -1):
            display(HTML(df.to_html(index=False)))