I made a couple of tkinter windows in Python. They both work and do what I want.

I assigned 2 launchers to them with a file like this in /home/pedro/.local/share/applications

and I locked the launchers to side panel in Ubuntu.

When I click one of my launchers, the window opens and I see a grey square with a question mark in it in the launcher panel. I suppose that is the default when no icon is assigned to the window.

Where can I assign a different icon to my window?

Do I need to do that in Python, or where??

I am unfamiliar with the Ubuntu launcher panel, but:

• does /home/pedro/icons/icon1.png exist?
• have you tried using an xdg icon name or have you tried moving icon1.png to /usr/share/pixmaps, or into the /usr/share/icons/hicolor/subfolder theme? In that case you could just call it with "Icon=icon1"

The launcher panel is a panel you can place left or right or bottom, I think. I set to "autohide", so it pops up when the mouse goes to the left side of the screen. My one contains a launcher for Firefox, Libre Office, other things.

My icons for my personalized launchers show up fine in the launcher panel.

But when I click the icon, the window opens and another icon appears in the launcher. That icon is the grey square with a question mark. It must be some kind of "default icon" for a window which has no icon assigned to it.

I found a solution in tkinter.

My master window is called master. I made a little icon with the text PyWin, it shows up nicely:

"True" passes the icon to other windows which open from the master window when I click a button. The master window already has its own icon.