To irregularly place the items on the canvas, we will generate the coordinates using the randint function from the random module. The item color will be randomly chosen as well by calling choice with a predefined list of colors.

Once generated, items can be deleted either by triggering the on_click handler when clicked or by pressing the Clear items button, which executes the clear_all callback. These methods internally call canvas.delete() with the appropriate parameters:

import random
import tkinter as tk

class App(tk.Tk):
    colors = ("red", "yellow", "green", "blue", "orange")

    def __init__(self):
        super().__init__()
        self.title("Removing canvas items")

        self.canvas = tk.Canvas(self, bg="white")
        frame = tk.Frame(self)
        generate_btn = tk.Button(frame, text="Generate items",
                                 command=self.generate_items)
        clear_btn = tk.Button(frame, text="Clear items",
                              command=self.clear_items)

        self.canvas.pack()
        frame.pack(fill=tk.BOTH)
        generate_btn.pack(side=tk.LEFT, expand=True, fill=tk.BOTH)
        clear_btn.pack(side=tk.LEFT, expand=True, fill=tk.BOTH)

        self.update()
        self.width = self.canvas.winfo_width()
        self.height = self.canvas.winfo_height()

        self.canvas.bind("<Button-1>", self.on_click)
        self.generate_items()

    def on_click(self, event):
        item = self.canvas.find_withtag(tk.CURRENT)
        self.canvas.delete(item)

    def generate_items(self):
        self.clear_items()
        for _ in range(10):
            x = random.randint(0, self.width)
            y = random.randint(0, self.height)
            color = random.choice(self.colors)
            self.canvas.create_oval(x, y, x + 20, y + 20, fill=color)

    def clear_items(self):
        self.canvas.delete(tk.ALL)

if __name__ == "__main__":
    app = App()
    app.mainloop()