TkInter: draw one pixel

After creating a Canvas object, you can draw a line that spans a single pixel.

your_canvas_widget.create_line(x, y, x + 1, y)

To create a single pixel with co-ordinates x, y on a canvas, you can use a rectangleobject:

canvas.create_rectangle( (x, y)*2 )

By default, the rectangle object has a one-pixel wide black border, which when one-pixel wide will just be black, regardless of the colour. To give the pixel your desired colour, you can use outline="", so you can then specify your fill colour.

I prefer this method as you only need to provide the x, y co-ordinates, no x+1 is needed.