def convert_ax_c_to_celsius(ax_f):
 (y1, y2) = ax_f.get_ylim()
 ax_c.set_ylim(fahrenheit2celsius(y1), fahrenheit2celsius(y2))
 ax_c.figure.canvas.draw()

def convert_ax_c_to_celsius ( ax_f ) : ( y1 , y2 ) = ax_f . get_ylim ( ) ax_c . set_ylim ( fahrenheit2celsius ( y1 ) , fahrenheit2celsius ( y2 ) ) ax_c . figure . canvas . draw ( )
update second axis according with first axis .