Giving it Borders

import tkinter as tk

class MoveCharacter(tk.Canvas):
    def __init__(self, parent, *args, **kwargs):
        super().__init__(parent, *args, **kwargs)

        self.dx = 0
        self.dy = 0

        self.height = 100
        self.width = 100

        self.start_X = 0
        self.start_Y = 0

        self.x = self.start_X
        self.y = self.start_Y

        # Create the box (character)
        self.box = self.create_rectangle(self.start_X, self.start_Y, self.height, self.width, fill="black")

        # Set update interval in milliseconds
        self.dt = 100
        self.tick()

    # Movement handler that gets called every dt milliseconds
    def tick(self):

        self.coordinats(self.dx, self.dy)
        wall_check(self.center)
        if not Dteck:
            self.move(self.box, self.dx, self.dy)

        if Dteck:
            self.coordinats(self.dx, self.dy)

        if not Dteck:
            # Reset the movement after each tick
            self.dx = 0
            self.dy = 0

        # Repeatedly call tick method to continue the movement loop
        self.after(self.dt, self.tick)

    # Method to change direction of movement
    def change_heading(self, dx, dy):
        self.dx = dx
        self.dy = dy

    def coordinats(self, stepx, stepy):
        self.x = self.x + stepx
        self.y = self.y + stepy

        self.center = [self.x + 50, self.y - 50]

def main():
    global root,character_canvas
    # Create the main window
    root = tk.Tk()
    root.title("2D Game")
    root.geometry("1080x720")
    root.configure(bg="black")

    # Create the MoveCharacter canvas (size 900x900)
    character_canvas = MoveCharacter(root, width=900, height=900, bg="lightblue")
    character_canvas.pack()

    keybindings()

    # Start the main loop
    root.mainloop()

def keybindings():
    global ds
    # Define movement step size
    ds = 100  # Smaller step for smoother movement

    # Bind key presses for movement
    root.bind("<KeyPress-a>", lambda _: character_canvas.change_heading(-ds, 0))  # Move left
    root.bind("<KeyPress-d>", lambda _: character_canvas.change_heading(ds, 0))  # Move right
    root.bind("<KeyPress-w>", lambda _: character_canvas.change_heading(0, -ds))  # Move up
    root.bind("<KeyPress-s>", lambda _: character_canvas.change_heading(0, ds))  # Move down

def wall_check(coords):
    global Dteck
    Dteck = False
    if coords[0] < 50 :
        character_canvas.change_heading(0, 0)
        Dteck = True
        character_canvas.coordinats(100,0)


    if coords[0] > 850 :
        character_canvas.change_heading(0, 0)
        Dteck = True
        character_canvas.coordinats(-100,0)

    if coords[1] > 750 :
        character_canvas.change_heading(0, 0)
        Dteck = True
        character_canvas.coordinats(0,-100)

    if coords[1] < -50 :
        character_canvas.change_heading(0, 0)
        Dteck = True
        character_canvas.coordinats(0,100)

    print(coords)

# Run the program
main()