On Creating Icons for Python Applications Using PyInstaller
The Basics
PyInstaller is able to take in Python3 packages and convert them into standalone executables of the .app or .exe flavor for Windows and MacOS. Today, I would like to discuss some extra information about its --icon command line option. It allows the embedding of a logo to be used as the app's icon in things like the file explorer, the dock on MacOS, or the taskbar on Windows. As such, it is not an entirely necessary addition to an app, but it makes the app seem more polished to an uninformed/end user. However, the file that can be specified as the command line option differs slightly depending on whether one is creating an app bundle or an executable. This will be explained in the following two sections.
Icns for MacOS
Apple uses the .icns icon format. This is effectively a directory of different sizes of the same image that the operating system can choose from to create the best visual experience for the end user. In order to create such a file one must first create a directory (e.g. MyIcon.iconset), and then populate the directory with the necessary images. Note: The directory name must end with .iconset or the second step will not work.
The images needed inside the directory are as follows:1
| Filename | Resolution |
|---|---|
| icon_16x16.png | 16x16 |
| icon_16x16@2x.png | 32x32 |
| icon_32x32.png | 32x32 |
| icon_32x32@2x.png | 64x64 |
| icon_128x128.png | 128x128 |
| icon_128x128@2x.png | 256x256 |
| icon_256x256.png | 256x256 |
| icon_256x256@2x.png | 512x512 |
| icon_512x512.png | 512x512 |
| icon_512x512@2x.png | 1024x1024 |
Note: For reasons unclear to me, MacOS does not in fact requrie a 64x64 icon size.
After these files have been provided in the MyIcon.iconset directory, then on MacOS, the following command can be used to turn this directory into a single .icns file instead:
iconutil -c icns "MyIcon.iconset"
This .icns file can then be included in the PyInstaller build using the afforementioned --icon CLI option
Ico for Windows
For Windows, the process is mostly similar, however it obviously does not use the Apple icns file format. Instead it uses the .ico file format. Using the, in my humble opinion, great CLI image editing program Imagemagick, one can create the ico file, including the necessary resized sub-images, with the following command:2
magick.exe input.png -define icon:auto-resize=16,32,48,64,256 -compress zip output.ico
As before, this ico file can then be included in the PyInstaller build using the --icon CLI option.
For more info see: StackOverflow↩
For more info see: StackOverflow↩