I'm trying to build a one-file EXE with PyInstaller which is to include an image and an icon. I cannot for the life of me get it to work with --onefile.

If I do --onedir it works all works very well. When I use --onefile, it can't find the referenced additional files (when running the compiled EXE). It finds the DLLs and everything else fine, just not the two images.

I've looked in the temp-dir generated when running the EXE (\Temp\_MEI95642\ for example) and the files are indeed in there. When I drop the EXE in that temp-directory it finds them. Very perplexing.

This is what I've added to the .spec file

a.datas += [('images/icon.ico', 'D:\\[workspace]\\App\\src\\images\\icon.ico',  'DATA'),
('images/loaderani.gif','D:\\[workspace]\\App\\src\\images\\loaderani.gif','DATA')]     

I should add that I have tried not putting them in subfolders as well, didn't make a difference.

Edit: Marked newer answer as correct due to PyInstaller update.

Newer versions of PyInstaller do not set the env variable anymore, so Shish's excellent answer will not work. Now the path gets set as sys._MEIPASS:

def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
    try:
        # PyInstaller creates a temp folder and stores path in _MEIPASS
        base_path = sys._MEIPASS
    except Exception:
        base_path = os.path.abspath(".")

    return os.path.join(base_path, relative_path)