How should I write the code so that when I click on any circle with the same mouse button, the circle turns blue?

Hey @tvcsop,

You saw your comment about the code being legit, having said that, I think you need to adjust the object_click_event method to change the color of the clicked item. You can access the clicked item using the tag_closest method and then change its color using itemconfigure.

Something like this one here:

import tkinter as tk

class CanvasEvents(tk.Tk):
    def __init__(self):
        super().__init__()
        self.geometry('510x510+700+100')
        self.title("Event")

        self.canvas = tk.Canvas(self, bg='grey', width=500, height=500)
        self.canvas.pack(pady=5)

        self.canvas.create_oval(20, 20, 100, 100, width=2, fill="orange", tags="kor1")
        self.canvas.create_oval(220, 20, 300, 100, width=2, fill="red", tags="kor2")
        self.canvas.create_oval(420, 20, 500, 100, width=2, fill="green", tags="kor3")

        self.canvas.tag_bind("kor1", '<Button-1>', self.object_click_event)
        self.canvas.tag_bind("kor2", '<Button-1>', self.object_click_event)
        self.canvas.tag_bind("kor3", '<Button-1>', self.object_click_event)

    def object_click_event(self, event):
        closest = self.canvas.find_closest(event.x, event.y)  # find closest item to the clicked point
        self.canvas.itemconfigure(closest, fill="blue")  # change color of the clicked item
        print('Clicked object at: ', self.canvas.coords(closest), closest)

if __name__ == "__main__":
    ablak = CanvasEvents()
    ablak.mainloop()

In the create_oval method, I added a tags parameter which can be used to bind the click event for each circle. The object_click_event method uses find_closest to find the closest item to the clicked point. It then uses itemconfigure to change the color of the clicked item to blue.

The code is legible, I forgot to enter it! https://www.onlinegdb.com/ODwJiVxOY