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