user interface - Python Tkinter Saving Point Coordinates -

i have python gui creating w/ tkinter. first time working w/ gui's , tkinter please bear w/ me!

i trying save point locations/coordinates variables. in code have far, upload bmp image, , when click on point on image, point marked. trying figure out how save first 3 points' coordinates variables in use create best-fit ellipse intersects 3 of points. how go doing this?

here code:

from tkinter import * pil import image, imagetk  class window(frame):     # define settings upon initialization.      def __init__(self, master=none):         # parameters want send through frame class.         frame.__init__(self, master)          # reference master widget, tk window         self.master = master          # that, want run init_window, doesn't yet          exist         self.init_window()      # creation of init_window     def init_window(self):         # changing title of our master widget         self.master.title("gui")          # allowing widget take full space of root window         self.pack(fill=both, expand=1)          # creating menu instance         menu = menu(self.master)         self.master.config(menu=menu)          # create file object)         file = menu(menu)          # adds command menu option, calling exit, ,         # command runs on event client_exit         file.add_command(label="exit", command=self.client_exit)          # added "file" our menu         menu.add_cascade(label="file", menu=file)          # create file object)         analyze = menu(menu)          # adds command menu option, calling exit, ,         # command runs on event client_exit         analyze.add_command(label="region of interest",          command=self.regionofinterest)          # added "file" our menu         menu.add_cascade(label="analyze", menu=analyze)         load = image.open("ap41.ddr.brf.sdat.bmp")         render = imagetk.photoimage(load)          # labels can text or images         img = label(self, image=render)         img.image = render         img.place(x=0, y=0)      def regionofinterest(self):         root.config(cursor="plus")         canvas.bind("<button-1>", self.imgclick)       def client_exit(self):         exit()      def imgclick(self, e):         x = canvas.canvasx(e.x)         y = canvas.canvasy(e.y)         pos.append((x, y))         canvas.create_line(x - 5, y, x + 5, y, fill="red", tags="crosshair")         canvas.create_line(x, y - 5, x, y + 5, fill="red", tags="crosshair")   # root window created. here, window, # can later have windows within windows. root = tk()  # loads exact size of image imgsize = image.open("ap41.ddr.brf.sdat.bmp") tkimage =  imagetk.photoimage(imgsize) w, h = imgsize.size  # creates canvas canvas = canvas(root, width=w, height=h) canvas.create_image((w/2,h/2),image=tkimage) canvas.pack()  # loads exact dimentsion img size geometry = "%dx%d" % (w,h) root.geometry(geometry)  # creation of instance app = window(root)  # mainloop root.mainloop()   

to save positions lets use list. can store tuples in class attribute.

lets move imgclick function class can take advantage of class attributes easier.

then lets remove init_window method redundant here.

also lets add counter when reach 3 clicks program stops marking map , removes button bind.

new class attributes:

self.pos = [] self.counter = 0

then modify imgclick method:

def imgclick(self, event):      if self.counter < 3:         x = canvas.canvasx(event.x)         y = canvas.canvasy(event.y)         self.pos.append((x, y))         print(self.pos)         canvas.create_line(x - 5, y, x + 5, y, fill="red", tags="crosshair")         canvas.create_line(x, y - 5, x, y + 5, fill="red", tags="crosshair")         self.counter += 1     else:         canvas.unbind("<button 1>")         root.config(cursor="arrow")         self.counter = 0 

you notice there print statement print out saved values of self.pos on each click during analyze clicks.

take @ code , let me know think:

from tkinter import * pil import image, imagetk  class window(frame):      def __init__(self, master=none):         frame.__init__(self, master)          self.master = master         self.pos = []         self.master.title("gui")         self.pack(fill=both, expand=1)          self.counter = 0          menu = menu(self.master)         self.master.config(menu=menu)          file = menu(menu)         file.add_command(label="exit", command=self.client_exit)         menu.add_cascade(label="file", menu=file)         analyze = menu(menu)          analyze.add_command(label="region of interest",          command=self.regionofinterest)          menu.add_cascade(label="analyze", menu=analyze)         load = image.open("ap41.ddr.brf.sdat.bmp")         render = imagetk.photoimage(load)          img = label(self, image=render)         img.image = render         img.place(x=0, y=0)      def regionofinterest(self):         root.config(cursor="plus")         canvas.bind("<button-1>", self.imgclick)       def client_exit(self):         exit()      def imgclick(self, event):          if self.counter < 3:             x = canvas.canvasx(event.x)             y = canvas.canvasy(event.y)             self.pos.append((x, y))             print(self.pos)             canvas.create_line(x - 5, y, x + 5, y, fill="red", tags="crosshair")             canvas.create_line(x, y - 5, x, y + 5, fill="red", tags="crosshair")             self.counter += 1         else:             canvas.unbind("<button 1>")             root.config(cursor="arrow")             self.counter = 0   root = tk() imgsize = image.open("ap41.ddr.brf.sdat.bmp") tkimage =  imagetk.photoimage(imgsize) w, h = imgsize.size  canvas = canvas(root, width=w, height=h) canvas.create_image((w/2,h/2),image=tkimage) canvas.pack()  root.geometry("%dx%d"%(w,h)) app = window(root) root.mainloop()