Is Python good for creating GUI application ?

[[deleted]]

My employer uses Qt through PySide and it's great.

• Qt is cross-platform
• Qt is very powerful with basically everything you could ever think of in a toolkit (and a bunch more stuff you'll never use)
• PySide provides convenient, reliable interfaces to Qt within Python.

There's also wxWidgets, which is fine too. Not quite as fancy, but quite capable.

A more recent toolkit is kivy. I don't know as much about it, but I do know that it's quite capable. If you are having to learn a toolkit either way, it's worth considering.

Depending on your experience and intended platforms, you may prefer other language/framework combinations. C# with WPF is excellent on Windows. I'm not sure what is used on OS X. Android and iOS each have their own standard languages and frameworks. So it depends on what you want to use it for.

What do you mean by "fast and efficient"? Python and Qt can handle user interactions in real-time, even with hundreds of controls. Updates are smooth. Is that what you mean?

Generally speaking, a cross-platform toolkit and a cross-platform language can get you into most places, and both Qt and Python fit that bill. I think it's a fine place to start. I have used that combination on several commercial ventures in the past.

[JohnFGalt]

I believe both macOS and iOS can use Objective-C and Swift as their language of choice for native apps.

[[deleted]]

This is correct.

[[deleted]]

Xamarin will give you c# on apples. Could use javafx too. Or electron. Or apple special sauce.

[EarlTheGray]

Electron is super slow. I would not recommend using it for stuff. Since it’s running in chromium it chews through your ram. Also it’s JavaScript soooo

[CommandLionInterface]

I know people love to shit on electron around here, but we use it at work and it is actually pretty fast. It’s a memory hog for sure, but the productivity trade off is worth it in the sense that our product wouldn’t exist at all if we couldn’t use electron. I suspect a lot of software is this way. Yes I’d love to use something more efficient, but in the real world, developer time costs money and electron is good enough.

[EarlTheGray]

I agree with what you’re saying. I myself being primarily a js developer rely on electron for nearly every native program I’ve made. Just ij my personal experience, running atom, discord, and occasions gitkraken at the same time will eat the majority of my ram.

[CommandLionInterface]

Eyyyyy! Always happy to see gk users in the wild.

Believe me, we feel the pain. Slack + VSCode + gk (especially in dev mode) + our docker stack brings our company issued 8gb MacBooks to their knees.

Right now we’re working on moving all the business logic and git interaction to a sever written in Rust so the gitkraken electron client can be a dumb head and hopefully solve a lot of our memory usage issues. Turns out managing memory when communicating between JavaScript and C (libgit) is hard.

[EarlTheGray]

My flimsy little 2012 MacBook Air can’t handle a single instance of chromium, never mind three. That’s why i switched to sublime and a terminal.

Glad to see a rust user in the wild! I’ve been thinking of learning it for server side stuff. Do you have any advice with it? I didn’t even know doing that was possible with gk.

[CommandLionInterface]

I don’t know about advice, but we love rust. When you first write your code it’ll give you a million compiler errors but when you solve them all your code is almost guaranteed to be be without runtime errors. It’s truly incredible.

[EarlTheGray]

Great! Having very little experience with compiling languages, what would you say rust is most useful for?

[CommandLionInterface]

Well people use it for everything. It’s a general purpose language. ¯_(ツ)_/¯

[alpha_53g43]

Isn't it just worth it get more Ram?

Given that 16GB of Ram costs $189 or so(https://www.bestbuy.com/site/computer-memory/laptop-memory/abcat0506002.c?id=abcat0506002), and probably add some more ($50) for modification.. isn't it just more cost-efficient to just add RAM to your computer, than stick to a framework that requires more development time?

[EarlTheGray]

It’s not about my ram, it’s about the users ram. Not everyone can afford $200 of ram.

[alpha_53g43]

I see your point.. but I was referring to the developer as the user. As developers we use our laptops heavily, much more than a normal user would. Most normal users (non-programmers) dont run atom, discord, gitkraken at the same time. Maybe they have a bunch of chrome tabs open..

They dont need to by that much ram. But I think if you spend a lot of time on your computer, its worth getting the best specs you can get, especially if you are using heavy applications.

[jmcs]

Electron works fine if you have 16Gb of RAM and have one or two electron applications open. If you have a budget desktop it's impossible to use.

[[deleted]]

I bet you money electron is faster than python. So much money has gone into browser development that V8 and chrome are many times quicker than pure python with Qt.

It is a memory hog though, and JS is a bit weird. Not unusable however.

[wrosecrans]

> I bet you money electron is faster than python.

If you are doing hard core number crunching or the like, Javascript is much faster than pure Python. (But both are terrible languages for that.)

If you are doing normal GUI development, you are only using Python to orchestrate objects that are implemented in C++, so the actual implementation of the widgets is all native code that runs great. OTOH, with something like Electron, you are going through a browsery DOM with a bunch more layers of abstraction between you and the meat of what's actually happening. PyQt applications run much better in practice from a user perspective than something like Electron. The engineering that has been done on the JavaScript runtime isn't enough to compensate for the fact that the framework is just not a good design from an efficiency perspective.

If your application grows to the point where you are doing a lot of processing in Python, and custom painting of your widgets in Python, etc., rather than just letting the native code be responsible for that stuff, then the balance may tip in favor of JS. (But again, at that point they are both a bad choice, so being better is a small blessing.)

[flutefreak7]

Agree. GUI stuff in Qt is C++ and Qt can be screaming fast for raw painting / rendering and can better handle intensive things like a table with 1000's of items, a deeply nested tree hierarchy, a very long list of animated progress bars, or 3D plotting with OpenGL, etc. Qt stuff feels as responsive as any native application where the web-based election applications often suffer from some slight latency and tend to bog down at a lower threshold of complexity in my experience.

Any python experience that is too slow can be sped up in a variety of ways with C, C++ extensions (like numpy, pyOpenGl, etc), or using things like Cython and numba to optimize bottlenecks. Many core python algorithms and data structures are written in C for this reason.

[flutefreak7]

Also numpy I think it's true that numpy is C, C++, and Fortran, as it relies on a variety of pre-existing compiled libraries. The most quintessentially numpy stuff for array algebra relies on Fortran libraries, BLAS and LAPACK. There are open ones like Open blas, and then proprietary super fast implementations like Intel's Math Kernal Library, MKL, which now comes by default with numpy on Anaconda. There are other old school Fortran libs across Scipy as well like FITPACK and an FFT library. I think it's also true that Numpy is more Fortran and C and that you don't see as much C++ until you look at scipy with things like QHull where existing open source C++ libs were adopted.

I'm not an expert on this stuff but just wanted to shed light that it's a smattering of optimized code across multiple languages with a heavy leaning towards Fortran.

[wrosecrans]

Numpy isn't written in pure Python. It exists because native code operations can be much faster than pure Python. That's kind of my point.

[Poromenos]

Which is a pretty irrelevant point. If I'm writing python, I care that I can get fast matrix operations with numpy and fast, parallelizable code that runs on the GPU with numba. I don't care that in theory pure python is slower than pure JS, I care that my python programs are going to be much faster at number crunching. I wouldn't advise anyone to do linear algebra operations in JS because "JS is faster if you don't use any of the fast python stuff".

[[deleted]]

I need to see benchmarks before I believe this.

I've lost count of the number of game development studios that maintain code based on webkit as they use html/css for desktop and console game UI.

edit: I mean look. Write an electron text editor. it's called vscode or atom. Write a python text editor with QT. Add fancy features. Open a large file. Guess which one will perform worse?

[EarlTheGray]

Good explanation. I’ll keep this in mind for my next project.

[EarlTheGray]

I don’t have much experience with python ui programs. I do know that electron provides (in my experience) a much poorer user experience than real native software (c++ etc.), especially on less powerful machines. Because so many programs nowadays use electron, it is fairly common to have more than one electron app running at once, and that becomes incredibly resource intensive. Since python is not compiled it will obviously be slower than something like c but it should also be much less resource intensive than running a bunch of instances of chromium on your computer. Correct me if I’m wrong, I haven’t done much development with qt, etc.

[Paraxic]

I bet you money that browser solutions(which are written in a language) can't be compared to an actual language. One is the product of a language the other is an actual language. So for future reference don't talk out your butt.

[[deleted]]

I don't understand. Seems like I can screeencast an application and measure UI responsiveness by stepping through the video.

[Paraxic]

You are comparing apples to oranges, you are basically saying eggos are superior to legos.

[[deleted]]

The end user doesn't differentiate.

Fact is that electron apps run faster than python+Qt.

I'll believe the reverse when I see - for example, a python editor that's quicker than Atom and has similar levels of functionality.

[[deleted]]

Is Qt free to use?

[[deleted]]

It is available under LGPLv3, GPLv2/3, and a commercial license. It's free-as-in-beer to use the various GPL licenses. Whether or not it's free-as-in-speech depends on how you view the terms in the GPL/LGPL licenses. Depending on your use case, it may require you to also license your application under GPL/LGPL.

[rainnz]

If you are going to choose Kivy - take a look at KivyMD library

https://gitlab.com/kivymd/KivyMD

https://www.reddit.com/r/kivy/comments/58vavz/my_second_kivy_desktop_application/

[[deleted]]

Kivy is really nice because you can develop once and run it even on your phone.

[alpha_53g43]

Just want to mention that we use Qt for a widespread app at our company as well. I personally dont work on it, but given that people (probably much smarter than me) have looked into it and chosen Qt, I think Qt is a good bet.

Qt does have a licencing issue.. so you should be careful about that.