python - Function being called even though Matplotlib button hasn't been clicked -

i have program shows image (fig 1). when image clicked shows colour in image clicked in separate matplotlib window (fig 2). fig 2 has buttons call different functions when clicked.

my problem functions meant called in fig 2 being called when fig 1 clicked.

the code looks this:

def show_fig1(img):   # plot image   plt.figure(1)   ax = plt.gca()   fig = plt.gcf()   implot = ax.imshow(img)    # detect click on image   cid = fig.canvas.mpl_connect('button_press_event', on_pixel_click)   plt.show(block=true)  # called when fig1 clicked def on_pixel_click(event):   if event.xdata != none , event.ydata != none:     # computation here gets image fig2     img = get_fig2_img()         show_fig2(img, event)   def show_fig2(img, event):   plt.figure(2)   plt.imshow(img)   # specify coordinates of button   ax = plt.axes([0.0, 0.0, 0.2, 0.1])    # add button   button = button(ax, 'button')   # detect click on button   button.on_clicked(test())   plt.show(block=true)   def test():   print "button clicked" 

so test() called instantly when on_pixel_click() called though theoretically should wait until button clicked because of button.on_clicked() command.

any help?

thanks in advance :)

on line:

button.on_clicked(test()) 

you telling python execute test function, rather passing reference it. remove brackets , should sort it:

button.on_clicked(test)