fig = plt.figure()
ax = fig.add_subplot(projection=ccrs.LambertConformal(
                       central_longitude=10, central_latitude=30))
ax.set_extent([-20,40,20,60])
ax.coastlines()
ax.gridlines(draw_labels=['right', 'bottom'],
             xlocs=np.arange(-180,181,10), ylocs=np.arange(-90,91,10),
             x_inline=False, y_inline=False,
　            **{'linewidth':0.5, 'color':'silver', 'linestyle':'--'})