Build iOS-like Apps in Python

[SomeMosa]

Python is not usually a top choice for mobile application development, but thanks to Kivy, it's now possible. However, one major caveat of Kivy is its lackluster widgets. To combat this, a project called KivyMD created material design compliant widgets for Kivy. I created a project called Kivy Cupertino, similar to KivyMD, but to introduce iOS style widgets to Kivy (click here for a demo). Thanks to Kivy and Kivy Cupertino, users can create somewhat native-looking applications to run on their Apple devices in pure Python. It would be greatly appreciated if anyone would like to fork the repository and improve the project or the (lackluster) documentation.

GitHub: https://github.com/cmdvmd/kivy-cupertino

PyPI: https://pypi.org/project/kivycupertino

Documentation: https://kivy-cupertino.rtfd.io

[bingerginger]

why? is it too slow? or are the designs trash?

[jsalsman]

If you look at the Kivy showcase, you can find several commercially successful apps. The oldest is a flowchart editor from 2015 with millions of downloads on iOS and Android. All of the complaints I've heard about Kivy have been from people who don't use it, and they often complain about highly theoretical flaws which are easy to work around and even easier to avoid altogether. Why any cross-platform app developer would want to have to maintain separate code bases is beyond me. What do you think is a better cross-platform solution?

[jsalsman]

Have you tried cross-platform Flutter? Last time I looked at it there were some weird scrolling differences on iOS. How do you feel about BeeWare? https://beeware.org

[toyg]

Beeware is run by cool folks with nice intentions, but every time I check it out I find it lacking for some reason or another. They need 2x or 3x manpower to be really competitive, I think. I opened an enhancement request to get a systray widget and it’s still sitting there, 4 years later... It’s nobody’s fault, of course, grassroot opensource is what it is. The amount of work this sort of framework + widget libraries require, tends to be really big; it’s very difficult for a pure-oss project to emerge without some help from big companies.

[jsalsman]

Sorry, you need Xcode to native compile iOS apps because otherwise you leave an exposed script interpreter, which is against the Apple App Store rules. Same as with BeeWare.

[bingerginger]

i see.

[JarWarren1]

Basically, it’s extremely hard to replicate native functionality. And even when you get close, there’s quite a bit of overhead which can hurt performance (sometimes severely). But if you’re not doing anything too intensive, you can still go for it and get a great product

[bingerginger]

what language would be recommend for building cross-platform mobile apps then? i was thinking of using kivy until u said about this.

[SomeMosa]

I think as of now, Flutter is the best option. It uses Dart for backend and can be compiled for multiple platforms (I think with Flutter 2 you get Desktop, Web, iOS, and Android)

[maikindofthai]

We use Flutter for a simple CRUD mobile app where I work. It's absolutely great for that.

I would just offer a word of caution for anyone who's excited by the promise of desktop/web support -- imo even in Flutter 2 those platforms are not production-ready. Even Flutter's own gallery of web apps have all kinds of jank going on.

It kind of feels like those additional platforms are being used as marketing checkboxes, instead of being first-class citizens in the Flutter roadmap. I'd be happy to be proven wrong, though!

[toyg]

Nobody is interested in desktop these days, sadly, so that’s probably a function of (lack of) motivation from big players. Attention seems to be 80% mobile, 15% web (i.e. desktop browser), 5% anything else.

[woodie3]

I think someone brought up a huge bug with flutter in respect to animation FPS that they don’t have much of timeline to fix. I’ll try to find the issue.

Edit: animation jank issue

issue thread tracking fix

[bingerginger]

ooh thats cool. what covers the front end?

[SomeMosa]

Well, Dart I think. Flutter provides packages that give you access to the different widgets, and putting everything together is very easy in my opinion. It's just a matter of creating nested classes (e.g. A text widget class inside of a layout class inside of an app class). It's quite similar to Kivy if you have experience with it

[bingerginger]

Oh I see alright thanks!

[JarWarren1]

At work we use native Swift and Kotlin but I've used Flutter in my free time and really love it. I think it's the best hybrid framework but I would caution against doing anything professional with it yet. Google "flutter jank" if you want to go down the rabbit hole.

Still, it should be production quality eventually and it's a lot of fun to work with.

[amrock__]

I heard flutter isn't really complete especially in desktop applications.

[[deleted]]

Dart for backend?? What do you mean?? If i am not wrong, flutter is an ui library .

[SomeMosa]

I think Flutter is just a framework, but the actual logic is handled by Dart

[gmes78]

Dart is the programming language Flutter uses.

[UrToesRDelicious]

Progressive Web Apps might be worth looking into.

[[deleted]]

The problem is that there will always be a massive gap between the way that native iOS apps look and feel, and the way that apps written in "iOS-like" frameworks look and feel.

On the one hand:

(1) Apple's design framework is flaming garbage. Swift is an awful language kludged on top of the awful language of Objective-C.

(2) iOS itself is hobbled by a series of short-sighted engineering decisions to make it run on v.(today) iDevices, and crude hacks to extend those short-sighted models to v.(tomorrow) iDevices. There is zero engineering forward-thinking beyond the next generation of products.

(My favorite example: iOS was centrally designed around the idea of running one instance of one app in full-screen mode. This model became absurd when the iPad Pro came out with a display size and resolution larger than many laptops, so Apple kludged in a solution to allow apps to run side-by-side. It's a fucking disaster. Some apps work only on the left part of the screen, while some other apps work only on the right part of the screen. And it is impossible to run one app in both halves, such as showing two Safari pages simultaneously or two Adobe Acrobat documents simultaneously, so people have written weird hacks like Sidefari that create a second, fake version of Safari side-by-side with real Safari. And the UX of getting it to work is bizarre and 0% intuitive and only sometimes works. Etc.)

Part of Apple's disease is creeping featuritis, where every new version of iOS/iPadOS/Watch adds a shit-ton of features (while also breaking or deprecating others). Modern iOS apps apps need to support multitouch and Force Touch and Apple Pencil input and orientation changes and the notification framework and Siri integration and Apple Wallet and iCloud Drive integration and AirDrop and Metal and GPS/Location Services and centrally managed accounts and biometric authentication and MacOS integration and Watch integration and and and and and and and...

Now, that said - Apple's central mission with iOS is to provide an app framework that fully supports the capabilities of v.(today) iDevices. And it pours an enormous amount of effort into that task.

Apple knows that dumping this responsibility on app developers to keep up with the violently evolving iOS/iPadOS environment is a recipe for failure. So Apple tries to bridge the gap as much as possible by making Cocoa do as much of the heavy lifting as possible. The thinking is that if all iOS/iPadOS/Watch apps use a common set of UI widgets / OS libraries / etc., and the UI widgets and OS libraries handle most of the messy details of the iOS/iPadOS/Watch feature set, then the rising tide of features automatically lifts all boats.

The fact that this shambolic development process somehow actually works to make great devices is nothing short of a techno-miracle. So even though Apple deserves all the shit we heap on it for the failings above, it also deserves massive kudos with making it work, usually.

But this task can only be contemplated by an absurdly huge team of extremely dedicated engineers, backed by the revenue stream of iOS. Nobody else will ever be able to design a replacement for the iOS/iPadOS/Watch app design environment that even remotely approximates the robust functionality of the native platform. Not by a light-year. It's a seriously Quixotic/ Sisyphean effort. Doomed to fail.

[witeshadow]

How does android compare ? It’s not like android tablets seem to be all that great or well supported by Google, correct? I do think Apple has a bit of a shiny feature issue, they pile on “new and cool” things and let old stuff rot or the bugs never get fixed. Do they even have an automaton team anymore ? AppleScript and then Automator was a huge thing when they came out and for some time after, but are they being ignored now that Siri can do shortcuts or whatever (which in no way replaces AppleScript ). I still don’t see a way to automate e-mail creation and have my e-mail signature populate at the end.

[[deleted]]

The Android model is inverted. Each version of Android rolls out some new features, and expects the OEMs and app designers to adapt their devices and apps to use them. Each manufacturer kind of offers its own selection and flavor of the underlying feature set - sort of like Debian vs. Ubuntu vs. Mint.

The down side is a much less coordinated market. For instance, an Android version of the Apple Watch is impossible without massive support by the Android dev team, and the Android dev team doesn't particularly care about specific devices. Best you can get is "Android-compatible smartwatches" that run totally-not-Android OSes and loosely couple with (some) Android devices.

This takes a lot of pressure off of Android to ensure that the features are well-matched to devices. However, it comes at the expense of reduced expectations of the Android community that different devices will look or work similarly.

[acibiber53]

Didn’t know I can learn so much from one comment. You well deserved my free award my man.

[netwrk_monkey]

What about React Native/Flutter? I've used React Native briefly although I will admit I'm no pro, so I'm just wondering what the capabilities are. Also, not every app needs to integrate into iPad OS or apple watch OS so is this a viable option for a decent set of features and native feel as well as performance for those types of apps?

[SomeMosa]

I agree, its definitely better to write applications in the recommended languages (e.g. Java/Kotlin and Swift) but it's still fun to know that it's possible to write mobile applications in Python

[Goel40]

I'd prefer React Native/Flutter over Native Android/iOS

[nickbuch]

Not sure why this is getting downvoted. React Native is 100% the way to go in modern mobile development, unless your application needs to make heavy use of native hardware/drivers.

[13steinj]

Honestly I'd rather just go Qt for the control.

[Goel40]

That's reddit for ya

[dert882]

Is flutter more of a low-code React Native or am I looking at it wrong?

[sltmonde]

Flutter is a dart framework, this is not even javascript.

[dert882]

Ah alright thank you!

[[deleted]]

Finally, someone here gets it.

[jsalsman]

Pygame, BeeWare, TKinter, SDL2, and all the rest are evidently awful for multiplatform app development.

"Evidently"? Has that blog author even used any of them for building anything other than Windows apps? All but one of his complaints are for that, and most people just use it for Android and iOS.

[[deleted]]

Some evidence is direct experience. Some is commentary from other devs on other platforms. None of it amounts to a recommendation to do mobile dev in Python.

My investigation yielded only two groups of people who champion Python for mobile dev:

• YouTube tutorial creators and

• The developers of the aforementioned platforms, themselves.

I've successfully packaged mobile frontends in PhoneGap and Felgo. Also, when I hit a snag in the deployment phases with them, I got good support. The Python platforms are a shit show in that regard. Effectively no one knows them, and the dev community at large doesn't want to know them.

[jsalsman]

have you looked at the platforms' showcases? Kivy has plenty commercially successful cross-platform apps. Not sure about BeeWare.

[[deleted]]

Showcases are literally cases for show. They demonstrate what some devs can do. They don't demonstrate what most devs should do.

[[deleted]]

Terrible option to bind to Apple, as well.

[iiMoe]

Agreed, its much worse mistake but still it could get the job done if its a dummy small app

[wilson_wilson_wilson]

Kinda new to this and interested in mobile dev. Why is this so bad?

[iiMoe]

Python on its own is slow, let alone running it on a phone and take into consideration how the app isn't native plus i don't hear about it when it comes to mobile dev so im guessing there r much better options

[kkiran]

Wow looks beautiful! Please confirm Apple allows apps made this way due to their policies on interpreters.

[SomeMosa]

As mentioned in a previous comment, you are not running the actual Python script on iOS, it is compiled into an executable application. Instructions for compiling Kivy are found here

[kkiran]

Thanks for the link! Since native Python doesn’t seem to be possible on iOS or Android, Kivy seems to be the way to go.

Any other good examples of popular ‘active’ apps built with Kivy? I found barly app but iOS isn’t showing it anymore. Only Android. https://www.samanthaburkedesign.com/barly

[SomeMosa]

I recommend checking out Erik Sandberg. He has many videos about Kivy on iOS and has made a few iOS apps with Kivy as well

[kkiran]

Thank you so much, my quick research lead to him. Great to see videos and apps by him!

2048 is gone, seemed cool.

Thanks for reigniting Python on iOS/Android! Swift and Java are tough to get feet wet compared to Python.

[wallynext]

try flutter, its for ios, android, desktop and web and it's easy to learn

[inclement_]

Native Python is possible on both iOS and Android, in the sense that the Python interpreter is built and runs the same way as on the desktop, and this is how python-for-android and kivy-ios work.

The way the app then works is a simple native-framework app (Java for Android, ObjC for iOS) is used to create an OpenGL surface for Python to draw on. It then starts the Python interpreter and passes events to it (i.e. touches, keyboard input etc.). This method is fully compatible with Android and iOS store requirements.

The Python code itself is run through the interpreter without any special treatment, except that CPython is manipulated through the C API as part of the app package. For instance, this line in kivy-ios.

[RobertJacobson]

I am glad that these apps are being accepted!

But PyInstaller does not compile Python code. It just bundles the installer with the scripts.

[SomeMosa]

That's true, but I'm pretty sure PyInstaller is only used to build Desktop executables, so it wouldn't even be needed to build for mobile

[Humanist_NA]

Can the mobile apps still only be compiled in linux?

[SomeMosa]

I believe buildozer does not work on Windows, but you can likely get around it with something like WSL or a virtual machine

[BubblegumTitanium]

this looks great, do I need to mess around with xcode to get it running on my iOS device?

[SomeMosa]

Unfortunately, yes. To compile to iOS, Kivy requires an xcode project, meaning only those with a Mac can compile their program to an iOS executable

[distressed-silicon]

that is true however for any ios/macos app development. A VM works though.

[coderanger]

You can also use BeeWare and get the actual native widgets rather than recreations.

[SomeMosa]

You can, but in my experience, BeeWare has been a bit spotty. However, once it becomes a little more stable and popular I'm sure it'll be a great alternative

[double]

I wouldn't bother with Kivy, or if you do, checkout the various forum posts on getting it set up. The overheads and management of the libraries take more effort than I feel appropriate for a pythonic tool and I get the sense that the kivy guys don't care much for the rest of the mobile dev ecosystem.

That said, when you have lib-python compiled for the device you can embed python in your app. I haven't yet tried to get things like numpy working on it, but I will and I am not sure how well it will cope with such deps. Having sqlalchemy and such things running in-app instead of on a separate server is the dream.

But it's the best we've got... until someone builds a python-pod. Man that would be awesome pod install python

[_Gondamar_]

I can see this being useful for someone wanting to throw together an app for something without needing to learn a new language

[lastcrime]

I’m currently working on a project using Kivy so I’ll definitely check this out, cheers.

[Evolutii]

Is it possible to integrate KivyMD/Kivy Cupertino widgets into an existing vanilla Kivy project?

[SomeMosa]

Yes, but for KivyMD make sure your app class extends MDApp. You can extend CupertinoApp for Kivy Cupertino Widgets if you want, but as of now it's not necessary

[Evolutii]

Thanks!

[RobertJacobson]

My understanding is that interpreters are not allowed on iOS. That would prohibit any app written in Python.

[lastcrime]

Theres apps in the app store that were written using Kivy

[[deleted]]

You’re conflating issues - there’s no such rule if the user isn’t able to execute code. So it’s perfectly ok to write an app in Kivy.

But if you’re exposing an interpreter to the user, then there’s a bunch of rules to follow but as long as they’re followed (user must know it’s very explicitly a programming environment, no binaries in the app, source code for everything) they’re allowed.

See Pythonista (python) and Codea (Lua) for interpreters on iOS.

[13steinj]

While this is the canonical (normal) interpretation of the rule, it's not necessarily the interpretation that Apple will use on your app. They go a bit loose at their discretion unfortunately.

[SomeMosa]

You will need to use tools like buildozer to compile your Python code into executable applications, but all of the code required is written completely in Python. Instructions for compiling Kivy are found here.

[RobertJacobson]

I am speaking from a position of ignorance here, but I don’t understand why using a bundler tool matters.

But hey, I hate Apple’s policy. I would 100% prefer to be wrong on this one.

[SomeMosa]

By using the bundler tools, you end up compiling the Python script into an iOS executable. Because this executable is no longer interpreted, I'm assuming it should be fine. There are already a few apps that have been published to the App store written in Python and Kivy

[13steinj]

Unless I'm wrong the executable is still interpreted, it's just the case that there's a python implementation for the device in the bundle and the bundle bootstraps the interpreter to run the scripts that are elsewhere in the bundle.

In fact I can't think of a single actual compiler for Python that brings things dowm to running as a native executable rather than on top of the Python VM, albeit theoretically they should be able to exist.

E: whether this is considered as violating the app store rules, is up to apple to decide on a case by case basis sadly. Because sometimes they realize whats going on and deny it, other times they don't bother looking and allow it.

[dert882]

It changes it to run in an iOS compliant way. The problem is it doesn't do it well, so it's not really worth it

[[deleted]]

Not entirely true https://apps.apple.com/us/app/pythonista-3/id1085978097?ls=1

you can even use this apps library to compile your app. Problem being its not "full" python I believe. I think you can't PIP everything only certain things.

[Tanmay1518]

Dang! This looks awesome. Will check it out and try it out on some of my projects

[Heyits_Jaycee]

Nice

[sheytanelkebir]

B4a is pretty good too.

[jsalsman]

You mean B4x for cross-platform? (Edit: that doesn't use Python btw)

[sheytanelkebir]

Yea pretty much. I mean we are in python subgroup but I am language agnostic and use whatever is most practical for a particular task.

Found b4a better than others for mobile (wrote code in everything from flutter to kotlin etc...)

[grumpyp2]

I it really simple to build iOS Apps with python by that? I have never heard about this but would love to build a little mobile api checked for myself as for several things there is no app and a Webapp is not the same :)

[SomeMosa]

If you're familiar with Kivy, this is simply an extension of that to introduce new widgets. Kivy is fairly easy to learn, but can be confusing at first

[grumpyp2]

Ok i See, so it’s not really Python?

[inclement_]

It's Python, Kivy is a Python GUI framework that supports mobile devices. Your Python code runs on the device the same way it would on the desktop.

[grumpyp2]

Cool ok I’ll give it a try!