matplotlib.backends# backend_mixed backend_template backend_agg backend_cairo backend_gtk3agg、backend_gtk3cairo backend_gtk4agg、backend_gtk4cairo backend_nbagg backend_pdf backend_pgf backend_ps backend_qtagg、backend_qtcairo backend_svg backend_tkagg、backend_tkcairo backend_webagg backend_wxagg、backend_wxcairo