How to embed Python for sidecar

[rkimoakbioinformatics]

I have a command-line based Python app. It uses some PyPI packages. I'd like to make a Tauri app which will call this Python app to do some operations and calculations. I read the documentation on the Sidecar feature of Tauri. I am still not sure how to use this. I am thinking about embedding the whole Python interpreter and packages somehow. Which folder in the Tauri project should I place the Python interpreter? What would be the best practice to embed a Python app inside a Tauri app? Would it work if I create a conda environment and install packages and my Python app in the conda environment, and then copy the entire conda environment folder to a subfolder of my Tauri project? I'd appreciate any help.

[FabianLars]

The most straight forward way is probably the same as for nodejs apps (using pkg). So you'd sidecar a packaged python app created with pyinstaller or something.

Or, if you're absolutely crazy and proficient in rust there's also this one: https://github.com/RustPython/RustPython. But i don't know how easy it would be to use it for a whole py project with dependencies (if it's even possible).

[ThatXliner]

Never mind, found it https://tauri.app/v1/api/config#bundleconfig

[FabianLars]

There is no guide-like documentation, only the config and api themselves. Then there is this repo example: https://github.com/tauri-apps/tauri/tree/dev/examples/resources

[JMMarchant]

@ThatXliner In theory yes, but it is more of a hassle. You'd have to bundle it as resources and then figure out how to run the executable inside it.

Is there a way to specify something in the resources folder as an externalBin? Been trying to make them interplay nicely but the binary then can't seem to find any of the other dynamic libraries in the resources folder.

[FabianLars]

Not as externalBin (that's the config to include sidecar binaries), but in theory the shell scope config accepts $RESOURCE dirs: https://tauri.app/v1/api/config/#shellallowlistscope - tbh no idea how reliable that really is.

An imo easier way to do it, until we implement resource mapping, would be to move all the resource files next to the tauri.conf.json (not inside a separate folder) - at least on windows all files should end up in the same folder this way.

Or maybe setting the cwd (current working dir) on the sidecar is enough?

[MGough]

Going a level deeper on this...

Is there a way to add firewall exceptions via WiX for a one-folder build. On a separate github issue this fragment was provided:

<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi" xmlns:fire="http://schemas.microsoft.com/wix/FirewallExtension">
  <Fragment>
    <DirectoryRef Id="TARGETDIR">
      <Component Id="FirewallExceptions" Guid="de95bf40-7d9c-4ee6-8c47-1a06f3b7ebe3">
        <fire:FirewallException Id="ArbitraryId1" Name="App Name (TCP)" Program="[!Path]" Profile="all" Protocol="tcp" Scope="any" />
      </Component>
    </DirectoryRef>
  </Fragment>
</Wix>

with matching config:

        "wix": {
          "fragmentPaths": ["./windows-installer/firewall-exception.wxs"],
          "componentRefs": ["FirewallExceptions"]
        }

but that targets the main application. Is it possible to add a fragment that targets the built binary in resources? I'm mostly unsure about what the appropriate path would be during the install, as it looks like [!Path] is the main tauri app?

[drumnicorn]

I created an Example Repo: https://github.com/cherob/tauri-rust-py

[rkimoakbioinformatics]

Thanks. I'll check it out.

[devilsnare007]

@drumnicorn, I just tried running your template with npm (replaced yarn with npm) and it fails to run, throwing the following error:
`[email protected] build_py

pyinstaller -F py/test.py --distpath src-tauri/bin/python --clean -n test-x86_64-pc-windows-msvc`
^^
EDIT: Nvm, I guess you do require pyinstaller in order to bundle the app, got it working after installing pyinstaller - thank you!

[tcardlab]

I did a little experiment that involved creating a client-side Flask server for various distributable WebView solutions (electron, tauri, FlaskWebGui). You can see an overview on the main branch and an example of the python sidecar on the tauri branch.

[simkimsia]

@tcardlab I’m interested in your example app. Not sure if this is the best place to ask a question, since I cannot find a place to write questions in the repo, thought I will write here.

Do you think it will be impossible to swap out the flask in your app for django?

I like to give it a shot just to experiment for my own learning.

[tcardlab]

Its been years since I've touched django, but it should be possible. You'll have to set manage.py as the entry and pass the relevant cmd-line args (or edit manage.py to run without args).

I used appData(windows) as the location for the sqlite database. You may be able to reference my code if you plan to do the same (I used appdirs lib).

Its worth noting that I and others have had trouble fully closing pyinstaller sidecars when closing the app. I just used a quick hack to check if the parent process still exists, otherwise the python instance self-terminates. (on discord, some have implied this is due to using pyinstaller single-file mode. I have not tested whether that is true or not).

Also, I had trouble finding recommendations on how to handle client-side DB migrations. So, be sure to give that some thought.

[tcardlab]

@simkimsia I hope you will share your code if you find success, I'd be interested to see it as well!

[NaCodermer]

i find a example for java Java sidecar for a Tauri + Angular app

[liudonghua123]

how about pyodide which use python wasm, pure web solution.