from tkinter import *
root = Tk()
root.geometry('500x600')
canv = Canvas(root, width=479, height=479, bg="#111")##padx='15', pady='80')
                  
def s():
    x1=0 
    d=24
    y=0
    y1=24
    for i in range(20):            
        for i in range(20):
            canv.create_rectangle(y,x1,y1,d, fill='#002', outline="#009") 
            x1+=24 
            d+=24
        y+=24
        y1+=24
        x1=0 
        d=24
s()
canv.pack(side='bottom')
root.mainloop()

 def lkm(self):
    canv.create_rectangle['black']='fill'
root.bind("<Button-1>", lkm)

 def lkm(event):  # не понимаю зачем тут тебе self.
    if event.keysym == "Enter":
        canv.create_rectangle["black"] = "fill"  # Менять цвет по-другому надо. Ты создаешь новый квадрат, и то не верно
root.bind("<KeyPress>", lkm)

 from tkinter import *
root = Tk()
root.geometry('600x600')
                  
def s():
    x1=0 
    y1=0
    for i in range(20):            
        for i in range(20):
            Button(root, command=click).place(x=x1, y=y1, width=30, height=30) 
            x1+=30
        y1+=30
        x1=0
s()
root.mainloop()

 from tkinter import *
root = Tk()
root.geometry('500x600')
canv = Canvas(root, width=479, height=479, bg="white")
spis = []
spis2 = []
                  
def s():
    x1=0 
    d=24
    y=0
    y1=24
    for i1 in range(20):            
        for i2 in range(20):
            m = y, x1, y1, d                     
            spis.append(list(m))
            x1+=24 
            d+=24
        y+=24
        y1+=24
        x1=0 
        d=24
s()
def click1(event):
    for i in range(400):
        if ((event.x > spis[i][0]) and (event.x < spis[i][2])) and (
            (event.y > spis[i][1]) and (event.y < spis[i][3])):
            canv.create_rectangle(spis[i][0],spis[i][1],spis[i][2],spis[i][3], 
                                  fill='#009',outline="#009") 
            m = spis[i][0], spis[i][1], spis[i][2], spis[i][3]
            spis2.append(list(m))
def click2(event):
    for i in range(400):
        if ((event.x > spis2[i][0]) and (event.x < spis2[i][2])) and (
            (event.y > spis2[i][1]) and (event.y < spis2[i][3])):
            canv.delete(i+1)
canv.pack(side='bottom')
canv.bind('<Button-1>', click1)
canv.bind('<Button-3>', click2)
root.mainloop()

 from tkinter import *
root = Tk()
root.geometry('500x600')
canv = Canvas(root, width=479, height=479, bg="white")
rect_size = 25 # размер квадрата
def click1(event):
            x_pos = event.x
            y_pos = event.y
            left = rect_size//2
            right = rect_size - left
            canv.create_rectangle(x_pos - left, y_pos - left, x_pos + right, y_pos + right,
                                  fill='#009',outline="#009")
def click2(event):
            canv.delete(CURRENT)
canv.pack(side='bottom')
canv.bind('<Button-1>', click1)
canv.bind('<Button-3>', click2)
root.mainloop()

 from tkinter import *
root = Tk()
root.geometry('500x600')
canv = Canvas(root, width=479, height=479, bg="white")
rect_size = 24 # размер квадрата
def click1(event):
            if canv.find_withtag(CURRENT): # проверка, есть ли там уже виджет
                return
            x_pos = event.x
            y_pos = event.y
            x1 = x_pos-x_pos%rect_size
            y1 = y_pos-y_pos%rect_size
            canv.create_rectangle(x1, y1, x1 + rect_size, y1 + rect_size,
                                  fill='#009',outline="#009")
def click2(event):
            canv.delete(CURRENT)
canv.pack(side='bottom')
canv.bind('<Button-1>', click1)
canv.bind('<Button-3>', click2)
root.mainloop()

 canv.gettags(all)

     z = []
    all1 = canv.find_all()
    for lk in all1:
        z1 = canv.gettags(lk)
        z.append(z1)