The most size-efficient way to build Windows app from a PySide app

[midnightdim]

I have an open source PySide app that I'd like to build and distribute as a Windows desktop app (and also Mac and Linux in the future).
I'm currently using cxfreeze with a build script to build the app and Inno Setup to create the installer.

I noticed that when I build the app with cxfreeze the biggest folder inside lib folder is PySide2. It's around 322Mb when I build it.
The app is rather minimalistic, so it's a bit confusing that even the packaged installer is almost 100Mb. I'd like to reduce this size as much as possible.

I noticed that I can delete some big files inside PySide2 subfolder and it doesn't affect the functioning of the app, because I'm not using the corresponding components: Qt5WebEngineCore.dll, Qt5Designer.dll, etc.

I also found that it's safe to delete some subfolders like examples, resources, qml and even translations.

So my questions are:

1. What's the best way to build an executable app from a PySide app for Windows (7,10)?
2. How can I get rid of unused files and folders? How can this be automated?
3. What's the best practice for building the app for Mac and Linux?

Thanks.

[ewerybody]

Hello @midnightdim 👋 I cannot say much about cxfreeze. According to the docs its one of the 2 that supports PySide6? nice.
Well. I dunno whats the best 🤷‍♀️ But I can tell about my process of building releases for Windows.

I'm using PyInstaller and some post assembly python scripts for cleanup and installer creation. My stats are:

• ~58.5mb for the unpacked PySide2 python app dir
• ~27mb for the zipped portable pack
• ~18mb for the installer executable using 7zip self extractor.

I saw other people talking about using UPX to compress some of the Qt-dlls but so far I'm happy with the sizes. So I didn't fiddle with it.

[midnightdim]

@ewerybody Hi and thanks!

Is it correct that you're shipping your app as a "portable version", i.e. without the installation?
I'm going to try reusing your finish_package.py, looks like it does some cleanup that I'm looking for.
Could you please shed some light on what's the best way to apply these scripts? What kind of tweaking do I need to use it with my app?
Is there a simpler solution? For example, just a script that would delete unused dlls?

Although I'm not using Qt6 yet, I'd really like to switch to PySide6/Qt6 in the future, so would be glad to hear the suggestions for building the app with cxfreeze. Or maybe pyinstaller is going to support it in the near future.

[Gojir4]

Hello @midnightdim,

First, did you try to use "exclude" argument in cxfreeze setup script ? It may help to reduce size according to this post on stackoverflow

Since you're planning to switch to PySide6, you may be interested by nuitka. It compiles Python code to c code and make a "true" executable. It's partially supported on PySide2 but seems PySide6 is fully supported. I didn't test it yet but it looks promising.

[midnightdim]

@Gojir4 Thanks. Yes, I'm using "excludes", but the question is: what exactly should I exclude (at least in PySide). I know what I'm using, does it mean that I have to review all PySide2 packages and add everything that I don't use to "excludes"?

And yes, thanks for the tip, I looked at nuitka and it looks promising indeed. Going to try it, but @ewerybody 's approach seems very solid, so I'm reaching out to him to get some further advice.