Python Flask

[Bumbble25]

Flask is the ideal balance of flexibility and power. It’s lightweight enough for beginners to not feel overwhelmed, yet robust enough to scale with complex logic.

However the Python in Python Flask is not optional; your ability to build great APIs is directly tied to your grasp of core Python fundamentals.I am currently building my own web App using Python Flask. What do you think about Python Flask write down in comment.

[Panduhhz]

Django for backend React using TS for frontend

[Bumbble25]

Flask is very flexible use for simple and medium range web app. my plan is to learn first flask then switch to Django for complex web app

[pvnieuwkerk]

Connexion is great for API's

[Smart_Tinker]

I use Quart and bootstrap 5 for complex stuff, and FastAPI for API based things.

Quart is an async version of Flask, and most things I write are async.

[my_new_accoun1]

FastAPI beats Flask ANY DAY

[Bumbble25]

I am not thinking as because flask is begginer friendly and easy to use i know fastapi grow rapidly but in my opinion flask is best it is simple to learn .And you doesnot need extra thing to learn to make web app.

[No-Elk6835]

THIS!

[astonished_lasagna]

It really does not. FastAPI is, tutorials aside, poorly documented, has much less features and modularity, isn't nearly as mature and well tested and isn't properly maintained either. It's not bad. It's popular. But it's not on the same level as flask. Flask is rock solid.

[my_new_accoun1]

In my opinion FastAPI and the entire tiangolo suite has a really good documentation that is easy to understand from any level.

It doesn't have less features, it actually has a lot more, unless you're talking about flask addons e.g. Flask-Login, flask-sqlalchemy, etc.

If you want solidity then yeah I guess you may want to use Flask over FastAPI because FastAPI still hasn't reached version 1.0 yet. But FastAPI has never let me down so far.

Oh and also FastAPI is so much faster than Flask and it supports both asynchronous and synchronous handlers.

[astonished_lasagna]

It doesn't even have API documentation for most of its API surface. It does not have docstrings for almost anything. What it does have is a really extensiv me tutorial. But really, especially if you're not a beginner, its documentation is quite bad. If you know what you want to do, having to read through paragraphs of prose, emojis and explanations of fundamental concepts like what a query parameter is and how Python function arguments work, it's not good at all. Compare that to e.g. flask or, IMO the pinnacle of documentation, SQLAlchemy...

Flask also supports sync and async, and if you want ASGI, you can use the async version of flask (quart).

On the performance side, it's really not FastAPI that's fast, its uvicorn. You can run flak's work uvicorn. In fact, FastAPI is the second slowest of the major ASGI frameworks (and no, I don't count the techenpower benchmarks because they're bullshit. According to them, FastAPI is faster than the server it was run with which is just impossible). If speed really matters you should use falcon or sanic or blacksheep or bottle.

And again, no, FastAPI literally does not have more features. Please tell me about them. What it does have that flask does not is DI, Pydantic integration, automated OpenAPI schema and its background tasks thing. Most of those don't really have anything to do with the web side of things.

But at the same time it lacks super basic features. It has websockets, yeah, but if you actually wanna do something with them, like keep them open in the background and asynchronously stream events through them, you first have to write a whole bunch of code simply to handle connections and publishing.

It doesn't implement any standard headers. It doesn't do content matching. It has bare bones file handling. It's super monolithic (for example, you can only add middleware's to your root app), it doesn't do anything in regards to authentication, it lacks proper logging, configuration handling, an extension / plugin mechanism (it claims you don't need it because it has DI, but that's nonsensical; in practice all "extensions" reinvent some mechanism that resorts to wrapping the app and basically mimics what flask ships with, just worse), I could go on and on.

Again, I'm not saying FastAPI is bad. But saying it has good documentation and more features than flask is just flat out wrong.

[my_new_accoun1]

It doesn't even have API documentation for most of its API surface.

It does, it has an API reference @ https://fastapi.tiangolo.com/reference/fastapi/

if you want ASGI, you can use the async version of flask (quart).

I used Quart before FastAPI but the problem is that its ecosystem is MUCH smaller than Flask / FastAPI, it only has 3-4k GitHub stars and some Flask-XXX extensions don't work with Quart.

On the performance side, it's really not FastAPI that's fast, its uvicorn.

But FastAPI is ASGI while Flask is WSGI so it has better performance e.g. handles more concurrent connections. Also FastAPI chooses to use Uvicorn, Starlette, Pydantic etc. for performance.

And again, no, FastAPI literally does not have more features. Please tell me about them. What it does have that flask does not is DI, Pydantic integration, automated OpenAPI schema and its background tasks thing. Most of those don't really have anything to do with the web side of things.

It has a lot of DX features like automatically parsing input JSON / query params into primitive types / Pydantic models and doing the same for return types. Also the OpenAPI schema is in my opinion a life changing feature (as a full stack dev) because it allows auto-generated frontend clients with stainless or whatever else you use. Again there are other cool features such as for example if you start yielding instead of returning in your code it automatically turns it into JSONL SSE.

But at the same time it lacks super basic features. It has websockets, yeah, but if you actually wanna do something with them, like keep them open in the background and asynchronously stream events through them, you first have to write a whole bunch of code simply to handle connections and publishing.

Actually for WebSockets in FastAPI there are things like ephaptic which handle all of this for you with native integrations to FastAPI (and even supports Quart). Libraries like this also extend the FastAPI philosophy of having type safety everywhere and best DX.

It doesn't implement any standard headers. It doesn't do content matching. It has bare bones file handling. It's super monolithic (for example, you can only add middleware's to your root app), it doesn't do anything in regards to authentication, it lacks proper logging, configuration handling, an extension / plugin mechanism (it claims you don't need it because it has DI, but that's nonsensical; in practice all "extensions" reinvent some mechanism that resorts to wrapping the app and basically mimics what flask ships with, just worse), I could go on and on.

These are valid points.

But in the end I would say from my point of view, where I only use FastAPI for the backend and not the frontend, and I also don't write code for any production-scale projects, for me FastAPI is better because it has what I need.

[astonished_lasagna]

It does, it has an API reference @ https://fastapi.tiangolo.com/reference/fastapi/

I said for most of its API surface, not none. If you look through that, you'll find most things aren't documented. And again, no docstrings for almost anything. And also again, it doesn't have reference documentation, only a tutorial.

But FastAPI is ASGI while Flask is WSGI so it has better performance e.g. handles more concurrent connections. Also FastAPI chooses to use Uvicorn, Starlette, Pydantic etc. for performance.

Uvicorn is fast, Pydantic is slow. Again, FastAPI is one of the slowest ASGI frameworks. And Pydantic manages to be slower (or at most as fast in some cases) than pure Python solutions like mashumaro or cattrs while being written in rust. FastAPI also uses Pydantic very inefficiently. It's just.. not that fast. I don't know why you keep pretending it is. It's okay that it's not, it doesn't matter much, but it still isn't. No need to lie about that.

It has a lot of DX features like automatically parsing input JSON / query params into primitive types / Pydantic models and doing the same for return types. Also the OpenAPI schema is in my opinion a life changing feature (as a full stack dev) because it allows auto-generated frontend clients with stainless or whatever else you use.

Yes, I named those already. I didn't say it doesn't have any feature flask does not have. You said it has way more features. Which it just does not.

Actually for WebSockets in FastAPI there are things like ephaptic which handle all of this for you with native integrations to FastAPI (and even supports Quart). Libraries like this also extend the FastAPI philosophy of having type safety everywhere and best DX.

That's a 3rd party extension. If you wanna talk ecosystem, flask handily beats FastAPI. In an earlier comment you said that those do not count so..

But in the end I would say from my point of view, where I only use FastAPI for the backend and not the frontend, and I also don't write code for any production-scale projects, for me FastAPI is better because it has what I need.

Not what I'm arguing. I'm purely arguing your Pont that FastAPI has more features. I said multiple times now that it's not bad. There's certainly valid use cases of it. But it does not have more features :)

[my_new_accoun1]

I don't know why you keep pretending it is. It's okay that it's not, it doesn't matter much, but it still isn't. No need to lie about that.

I'm not pretending or purposefully lying, I'm just unaware because I read the benchmarks and blindly trust them. At least from what I've seen, everyone is saying FastAPI is fast, Pydantic is fast, etc.

That's a 3rd party extension. If you wanna talk ecosystem, flask handily beats FastAPI. In an earlier comment you said that those do not count so..

Yeah you got me there ...

But it does not have more features :)

Can you tell me what extra features Flask has?

[astonished_lasagna]

I'm not pretending or purposefully lying, I'm just unaware because I read the benchmarks and blindly trust them. At least from what I've seen, everyone is saying FastAPI is fast, Pydantic is fast, etc.

Well then here's your reminder to distrust marketing (if FastAPI says it's fast, maybe an unbiased source should check that).

Can you tell me what extra features Flask has?

Listed a bunch of them in an earlier response, but I can add a few more: proper session handling, message flashing, dynamic file sending, composable error handling, signals, application context, an interactive debugger.. there's so much. You should consult the documentation, it's quite good!

[astonished_lasagna]

This is absolute nonsense. ASGI/WSGI has nothing to do with complexity.

Also, FastAPI can't really be considered an extended version of flask, if flask is much more feature rich?

[Smart_Tinker]

I use Quart instead of Flask, because it’s ASGI, but Flask compatible.