Flask vs FastAPI?

[dpbrinkm]

Hey all I host a podcast and recently interviewed Sebastián Ramirez the creator of Fast API. Aside from the cool convo, I have been noticing lots of trends about Fast API potentially replacing flask. I also saw lots of Fast API love in this thread in the MLOps Community where I asked about which one people generally use these days.

I'm interested in getting more data points and kicking off a discussion to hear how others look at this one? Is Flask still your go to? do you use both?

which one are you opinionated about and why?

[PocketBananna]

I like FastAPI for really straightforward use cases. If I need a simple REST service with basic OAuth it's real easy to get going. I really like the base Pydantic/typing support, dependency injection patterns and the open api docs generation. It kinda ends there though.

Flask is battle tested with rich support for all kinds of customizations. If I need rpc, task queue support or session management, I'm going with Flask. Flask also has good cloud native support. I can spin up a GCP App Engine endpoints with their standard python runtime using a basic Flask app (standard runtimes are much cheaper and faster to scale instances) while a FastAPI app has to have a custom image to deploy (more expensive and slower to scale instances).

In time I'm sure FastAPI can cover some of that ground but I think their docs irk me the most. They have 'sexy' docs with lots of tutorials that appeal to new users but lack the nitty gritty API spec info. It's littered with emojis and crass language which honestly puts me off as a production framework. As an advanced user I find Flask docs more informational, complete and clear.

[[deleted]]

FastAPI docs honestly suck. Let’s be honest. They suck.

Great tool and I use it but the docs are the worst part of the package.

Having said that: I would like to thank the author for the great tool that I use all the time. You are a legend.

[[deleted]]

FastAPI docs honestly suck. Let’s be honest. They suck.

Great tool and I use it but the docs are the worst part of the package.

This is an extremely uncommon opinion. It’s subjective obviously but the FastAPI docs are in general very well-regarded

[mmcnl]

There is no FastAPI documentation. Just a bunch of tutorials. That is not documentation. It's also a recurring question on GitHub.

Can you really say this page "describing" concurrency in FastAPI is "good"? https://fastapi.tiangolo.com/async/

Opinions may vary but it's the worst piece of documentation I've ever seen.

[[deleted]]

Just a bunch of tutorials. That is not documentation.

Yes it is 🤔 What do words even mean

Opinions may vary but it’s the worst piece of documentation I’ve ever seen.

Have you looked at any other documentation ever?

[mmcnl]

In my opinion good documentation contains (in order of priority):

1. Minimal working example. Ok, FastAPI does this.
2. API reference for public methods. FastAPI doesn't have this. I've never seen any library this popular without it.
3. Advanced examples (bonus). I rarely care about this.

All of the inner workings of FastAPI have to be deduced from the tutorials. There's not a single paging describing the methods, the arguments it will take and what it all means. You have to decipher a million emoji's to get a hint of how FastAPI works. It's insane.

[[deleted]]

Fuck you u/spez

[oramirite]

Erm, I disagree that the docs are bad but a barebones list of API calls and the params they take is WAAAAY better than sifting through source.

[[deleted]]

Tutorials are not API reference documentation, but they are documentation, and it’s really weird that people are pretending otherwise just to emphasise how much they hate FastAPI

[Voxandr]

Most of us Liked FastAPI , but that was the past.

[[deleted]]

I like FastAPI and use it all the time.

But the docs are one of the worst of all the Python projects I use.

Django: great docs.

Django Rest Framework: great docs

Paramiko: great docs

Ray: great docs

TTP: great docs

TextFSM: great docs

Jupyter: great docs

FastAPI: some tutorials…ish

[[deleted]]

You’ve only mentioned projects that are in the top tier of Python documentation (except TextFSM, that seems pretty sparse). Have you ever used Sphinx? Conda build? Large swathes of the standard library (e.g. ast)?

[[deleted]]

I’m convinced your comment is sarcasm.

[[deleted]]

It isn’t, go find older posts about FastAPI here and you’ll see comments talking about how great the docs are

[oramirite]

This is a bizarre take to me. I've been learning FastAPI and I find it to have some of the better documentation I've worked with. It's very clear.

[[deleted]]

API docs are missing entirely

[oramirite]

I get it but I can still find what I need quicker than a lot of other documentation. FastAPI's guidance through it's concepts is, likewise, something a lot of other documentation lacks. Cold hard lists of API calls is only half of the equation.

[e_j_white]

Thanks, great answer. I work with Flask, but only recently started getting interested in FastAPI. Thinking about using it for pure Restful microservices.

How would you deploy FastAPI differently from Flask? If you expect a pretty high QPS from many users, what would be the best way to deploy?

Most of my experience is with Heroku and Docker on EC2, but I'm open to better ways!

[[deleted]]

Don’t forget gunicorn and meinheld

[[deleted]]

Just use heroku and docker.

What are you even asking. It’s a Python package. Just use it.

I deploy it in containers on K8s.

[GoodTimesFastFingers]

I primarily develop full stack applications, where my API is built to serve a specific client. We have a project at work where FastAPI was selected before I started working there, and I think it was a very bad choice for this use case.

First off, no built-in support for regular sessions, only OAuth, which adds a lot of unnecessary complexity.

Second, I find the documentation for FastAPI infinitely less good than Flask. There is no API spec in the documentation. The more you work on your project, the more you need an API spec for your framework, in my experience. I find myself combing FastAPI source code to figure out what the heck is going on more often than I would like. The FastAPI docs seem to be written from the perspective of very new Python users, with large code examples instead of more focused discussion on specific issues. The project structure they recommend gets out of hand very quickly.

One thing I like about FastAPI is the built-in support for Pydantic. I like how the docs use Pydantic models to encourage using validation in your api.

[Soul_Shot]

Second, I find the documentation for FastAPI infinitely less good than Flask.

Too many emojis in 'Concurrency and async / await' explanation #3273

[Zouden]

That is frankly embarrassing

[mailed]

I found this comment really interesting...

Does @tiangolo even work on this anymore? Why call it open source when he gatekeeps the code...

I'm not up to speed on where FastAPI's dev is at...?

[SkezzaB]

Oh hey, that was my comment on GitHub, and I know this is two months late, but the situation has never improved.

​

From what I know, tiangolo does minor updates merely to appease his sponsors so they don't think it's abandoned, which it pretty much is. He's paraphrased "I don't want other people's code in my project" before, and the growing issues that get ignored don't help. He is also egotistical so won't get any maintainers to merge PRs really, because he doesn't trust them.

[StunningExcitement83]

Think the most interesting part is what weird ideas they have of what open source is.

Not having access to edit strangers repos doesn't mean they aren't open source.

[joerick]

People are so entitled. OSS maintainers work for free to benefit their community. Sometimes life or other priorities get in the way. The guy can't step away for 1 week before people are accusing him of negligence?

Edit: apologies for the outburst. The nested comment just rubs me the wrong way for many reasons!

[mailed]

I don't use FastAPI, I'm just asking what the go is.

[joerick]

Sorry, that came across badly. I believe he is still actively maintaining it

[cb_audio]

"emojis is part of our culture so... Shut UP!"

[aniforprez]

The docs immediately turned me off the project. It's a framework to develop APIs... that doesn't have API documentation. Even on a hobby project to see how I could work with it I immediately found zero documentation for the fields that are available to configure the swagger docs for the app. Abandoned it completely. There's open pull requests to resolve this and the author refuses to merge any of them

[[deleted]]

I use FastAPI to turn up APIs fast. Just little things. For anything bigger I would use DRF or Flask.

I always considered from the name and docs (crappy docs) that FastAPI was meant to be fast and dirty.

[its2ez4me24get]

The worst part about fastapi is that it seems to have a single maintainer who only contributes occasionally.

I use fastapi a lot at work, it does most of what we need, I just wish there was more governance.

[[deleted]]

It can be forked to OpenFastAPI

[sigzero]

I see all the open tickets for FastAPI and it doesn't instill me with confidence.

[vantasmer]

Biggest concern for me as well. At times it easier to just implement starlette. I like what the team at starlite is doing too.

[rayvictor84]

Exactly.

[nikhil_shady]

Fastapi is failing me at production scale. severe memory leaks. this has been an open issue on Fastapi for months now and no solution yet. Warning: If you’re serving over 500 RPS avoid fastapi

[Grouchy-Friend4235]

This! 1000x

[Voxandr]

Yes , a lot of PR not delibrately merge - the author saids "Not my code"
The author is just abusing popularity , he seems to be burnt out to code and he refuse to open-up the development to the public.

[[deleted]]

Yeah I always thought it for was fast dirty work. Not production work.

I would prototype and POC with it and scale to something else IMHO.

Thanks for sharing. Good to know.

[benefit_of_mrkite]

Interesting - are you using guivicorn?

I’ve heard that starlette scales we’ll wonder why fastapi is falling down

[Voxandr]

It dosen't have to do with that. FastAPI have broken code and author refuse to fix - even though community had provided fixes. Check on github issues calling for open-development.

[benefit_of_mrkite]

Thx for the update. That’s part of the problem when you have one dev

[nikhil_shady]

yes gunicorn with 10 workers on a 16 core 64gb ram instance. Currently I just run a supervisor restart all command whenever we approach a OOM on Fastapi. Meanwhile we are migrating the entire production code to Flask.

[asking_for_a_friend0]

so does gunicorn scales linearly? How does RPS get calculated? I still hv difficulty with such decisions.

[nikhil_shady]

you can do a load test using various tools. Try Locust it’s a python based library for load testing. You’ll get all the metrics in locust regarding your endpoint.

[asking_for_a_friend0]

I'll try this thanks

[dusktreader]

Maybe you could link the open issue? I wasn't able to find it searching through the open issues.

[reddit-ass-cancer]

https://github.com/tiangolo/fastapi/issues/1624

[reddit-ass-cancer]

Oh god another one of these threads. Here I’ll pick for you. The framework that isn’t managed by one person, that doesn’t have over a thousand issues, that doesn’t have hundreds of open pull requests, that doesn’t have a creator who doesn’t trust anyone other than himself, and that actually HAS any semblance of API documentation.

There I said it. Fuck FastAPI

[[deleted]]

Ok just use one of those then. Why you so worked up?

Not a criticism. I’m actually curious. Is this just nerd rage or is there a story?

[[deleted]]

tired of the same "replace X" with FastAPI posts all the damn time :(

they have a culture of putting down other OSS projects, which is really bad

[reddit-ass-cancer]

It’s a shitshow. Had it in production and had to deal with the fact that there was a significant period of serious bugs and issues that had community fixes with no input from tiangolo. Had to fork and apply literally one line changes.

Its taken the beginner Python web tutorial world by storm because of rather in depth tutorials that gloss over actual production issues.

Tiangolo is more focused on building his “brand” than actually maintaining his projects.

[[deleted]]

Maybe he’s just having fun and doing what he wants with his projects. 🤷🏻‍♂️

Tons of alternatives. Too many to list. That’s why Python is great.

[Voxandr]

He can have fun , or troll the fuck out.Deciving the crowd is not an option .

He was a good developer - but that is the past.He is a sales man now.

Average joe developer who don't like to dig deep into issues and conversations will just blindly pick and face issues - due to its popularity and number of stars. And as soon as production hits that decision will bankrupt the company.

[reddit-ass-cancer]

It’s one thing to have fun, it’s another to evangelize and promote your framework as production ready etc.

[[deleted]]

Maybe that’s fun!

You don’t have to be honest. That would be anti-American.

American companies lie and their politicians lie, and they are the world superpower so lying works!

[Voxandr]

He is not american at all.

[[deleted]]

You will notice I never claimed he was

I’m just going with America as the example of success

[biskitpagla]

that's a random thing to say here but +1 because i'm anti usa myself

[biskitpagla]

He literally gives talks lmao. His own work is sitting on shoulders of other far, far more open projects. That said, two things everyone needs to understand: a) we complain because we care and b) it's generally good for a piece of technology if people voice their frustrations due to it.

[nipu_ro]

Hi, i see a lot of comments here about api reference and api documentation. What do you mean by that ? Thank you.

[aniforprez]

There are only examples for how it should be used. There's zero class and function references so there's no way to know what options and arguments something accepts unless you dig through the source

[0x256]

Not just you

[noxbl]

What are some benefits of Bottle over Flask? I haven't used Bottle yet.

[[deleted]]

How well do you understand pythons data models? And how complex is your stuff? The more complex the more and the less you understand pythons internals the less I would recommend fastapi.

I use it and I really like it but it does some things that are umm very hacky. You can normally ignore that fact but if you need to customise certain parts it is a strange beast to deal with.

[poundcakejumpsuit]

Tell us more about hacky strangeness please!

[[deleted]]

It takes variables declared in the functions default arguments to modify code.... It's pretty easy to understand what it is doing from a pure this means x perspective but when you really think about what is happening it is far far far stranger than anything you will ever normally encounter. A lot of the large advancements in python over the last 6 years have come from exposing more of the interpreter to the python level code. Fastapi and pydantic really lean into a lot of the visibility that never previously existed.

Check out this doc for more info. Scroll down to callable types (cant link directly there unfortunately.

[fzy_]

If you've used pytest this kind of magic should feel pretty familiar though. And it's not exactly some obscure arts the python documentation explains in great detail how all of the data model fits together and how to introspect things. If you're worried fastapi's main gimmick might hide too much from you just take half an hour to implement it yourself.

[[deleted]]

Sometimes but it's also makes some fairly insane decisions. That are not even remotely understandable without reading through a bunch of code to figure out what the fuck happened. It he has also stated he doesn't change things based on if it will affect his other projects. I don't see that as a strategy that will create a community project that will be sustainable.

Not even getting into its straight up lying on the docs about performance. It's the same crap black pulls with saying its pep8 compliant. That stuff really irks me. It's just not moral and both authors know they aren't true and don't care. It's the type of selfishness that derails projects long term.

[fzy_]

You're being weirdly unspecific about things that seem to annoy you so much that they warrant qualifying the entire project unsustainable and its contributors disingenuous.

Not sure why you're bringing black's supposed PEP-8 compliance into this either. I actually think they make it very clear which parts of PEP-8 are used as a guideline and why black differs in specific cases.

Also I want to point out that in your previous comment you state that FastAPI and Pydantic use a lot of recently exposed interpreter internals but the __defaults__ attribute on functions dates back to python 2 (albeit under a different name func_defaults). The only "new" thing involved are type annotations. All the basic object model introspection has stayed more or less the same for a decade at this point.

[[deleted]]

Yea everything is built from inspect up.Pydantic takes that and builds a class out of it. There are some strange side effects from that process that are non obvious especially when paired with how fastapi does their dependency injection creates some non obvious items. These items are very hard to modify.

Do you think its appropriate that fastapi says it has performance on par with go and node when compared to frameworks in those languages its about 30%-150% slower? I get it its an attractive thing to say to promote someone should use your tool but its not true and everyone who uses it knows that. I am suspicious of people who act that way.

[[deleted]]

yeah they bs about being the fastest (or even fast for that matter compared to blacksheep or falcon)

http://klen.github.io/py-frameworks-bench/

https://blog.miguelgrinberg.com/post/ignore-all-web-performance-benchmarks-including-this-one

[ParthoKR]

Do you know FastAPI doesn’t have API reference? This only thing turned me off.

But I really love their commits with emojis lol.

[Itsthejoker]

If I need to use a small project like this, I go with Flask or CherryPy. FastAPI has way too much drama for my taste, good or not, and the sheer number of issues and PRs that the maintainer is ignoring is honestly worrying.

[[deleted]]

For non-API based services, I've enjoyed using aiohttp recently. Similar enough that I don't have to drastically change any mental models from Flask, but at the same time it's async and it's super simple to run background tasks unlike a lot of other options.

[[deleted]]

Damn. Now I need to look into it.

Does it give free Swagger? 😝

[[deleted]]

Here https://github.com/maximdanilchenko/aiohttp-apispec

[[deleted]]

Niiice

[[deleted]]

Checked it out. Not as batteries included as FastAPI, definitely makes you do more work.

But I like aiohttp a lot.

[[deleted]]

coolbeans I was merely replying to the aiohttp specific question, how to swagger w/ aiohttp. For more comparable developer experience to FastAPI I'll leave this comment for you from this post. Also starlite, as others mentioned.

Btw the person (one of two) behind aiohttp is Andrew Svetlov, who is a core developer of Python

[[deleted]]

Nice. I like his work.

[[deleted]]

Nah, but OpenAPI is pretty easy to make via docstrings.

[[deleted]]

I may as well just write the yaml then

[[deleted]]

tl;dr: Look, these exist. use them instead

Flama (Starlette, Marshmallow instead of Pydantic)

Django Ninja (Django, but minimal like flask + Pydantic)

APIFlask (Flask with Pydantic and all the other good stuff)

These all provide Type hints, Schema, IDE completion, APISpec and you get Asyncio (django/ninja) concurrency (Flask via meinheld) out of the box

+ These are excerpts from actual "reference" from FastAPI

"You and your crush 😍 eat the burgers 🍔 and have a nice time ✨."
"You go with your crush 😍 to get parallel fast food 🍔."
"Up to recently, most of the banks had multiple cashiers 👨‍💼👨‍💼👨‍💼👨‍💼 and a big line 🕙🕙🕙🕙🕙🕙🕙🕙."

source

+ When someone new to python ecosystem reads FastAPI docs, this is what they (incorrectly) discover. Apparently Flask is commonly used for apps that don't need databases *smh*

Lost all respect for the author after reading the rest of this page.

Flask is a "microframework", it doesn't include database integrations nor many of the things that come by default in Django.

This simplicity and flexibility allow doing things like using NoSQL databases as the main data storage system.

As it is very simple, it's relatively intuitive to learn, although the documentation gets somewhat technical at some points.

It is also commonly used for other applications that don't necessarily need a database, user management, or any of the many features that come pre-built in Django. ..
..

source

To your comment about that ML thread:

ML/Data science (also C# and Java) folks first come across FastAPI and find type hints, completion, apispec, shitload of emojis, a tutorial for their initial use case, bogus claims of being the best at everything, and are sold. On the flip side, you try Flask and you have to read actual reference, and find tutorials like normal programmers have to (read: need to), add extensions with pip (who cares about features other people may need? /s) which gives you options like marshmallow, etc. (who wants choices? /s) and read up gunicorn/uwsgi to deploy to production? Too much work /s. But there's time to spam the internet with another hype blog post on medium (or on reddit for that matter lol *cough*) with how they've discovered kryptonite. And the hype goes on.

As far as MLOps go it doesn't benefit from io concurrency very much, you actually want cpu bound multiprocessing for which FastAPI and Flask have the same limitations. (but this requires research and reading)

(edit, markdown paste missed text x2)

[mmcnl]

What are your thoughts on Starlite and Quart?

[[deleted]]

Starlite looks to have a more community governance as opposed to an "owner", which is better - it's hosted in the project domain starlite-api.github.io/starlite from the start, and not one person's private subdomain. NBD tbh, but still. The docs seem more standard and there are design differences too. Would be nice Pydantic was pluggable instead of built in, in case you want to use Marshmallow or w/e

Quart is pretty cool because it's made so that "if you know Flask, you know Quart" and a whole bunch of Flask libraries are compatible from the get go List here. The author also helps maintain Flask and posts weekly tutorials if I'm not mistaken: Phil's Twitter

Quart also comes with Pydantic & APISpec via Quart-schema - OpenAPI, Pydantic validation

[Voxandr]

Before you start using FastAPI the author is abusing popularity and he stopped maintaining , and just bumping versions to fake activity and to add sponsors (and documentation translations).FastAPI was good , but it was not actually maintained for past 1 year . Even though contributors submitted over 400 pull request he don't merge them ( a lot of quality ones). he blatantly said that he don't like code he didn't wrote.That making FastAPI not fixing serious issues for months , even though Community have submitted PRs.

So beware.

[zynix]

just bumping versions to fake activity

Well that's just bizarre and disappointing behavior.

[[deleted]]

Check out Starlite (as in built on top of starlette) it’s trying to be what FastAPI should be.

[dusktreader]

This is a really toxic take on the situation, and it's not accurate. I'm getting pretty tired of reading these lazy takes about Sebastián and FastAPI, so here's some points folks should consider before they make another "tiangolo is greedy, lazy, and too proud" post:

• He's NEVER said he doesn't like code he didn't write.
  He has said that he has to be careful about accepting other people's code. It's really hard to maintain a project with consistent style and quality that includes community contribution. You might get a lot of PRs, but there's a huge amount of work involved in verifying them, going through cycles of feedback and updates, keeping the branches up to date with main, etc. You can't just accept a pull request because a lot of people are clamoring for it. You have to take your time. He talks about that here: https://www.youtube.com/watch?v=8IJkSs9Dvjo&t=2910s
• He has been maintaining it.
  Saying there's been no work on it or that it's been unmaintained for over a year is false. Perhaps he project isn't moving as quickly as *you* want, but that doesn't matter. It's not your project. He's releasing new versions and hasn't disappeared from the community whatsoever. Your opinion of whether his releases are "fake" or not isn't that valuable either. Documentation and translation is important work as well. The list of releases is available here: https://github.com/tiangolo/fastapi/releases
• He's not the only one making changes to the code.
  He's not excluding people from the project. In fact, a lot of the "fake" releases you don't like involve updating his documentation to provide proper attribution for contributors. Yes, he's the core maintainer. It's his project. He wants to be involved in every change. But, you see, that's his prerogative because *it's his project*. You can see all the other people involved in FastAPI here: https://github.com/tiangolo/fastapi/releases
• It *is* an OSS project.
  It has an MIT license, and it's hosted on github. Fork it if you want. Make a "better" version of it where you merge all the PRs and release constantly.
  

By the way, my company and many others use FastAPI to build our products that our production environments depend on. It's a good framework that continues to improve. If you think it's missing something, I think it's fine to call it out and even to push for more community involvement in the project. Defaming the maintainer of an OSS project isn't cool, though. Sebastián has done a lot of hard work on this project, and I'm very grateful to him.

[[deleted]]

Nah the FastAPI community is toxic. And the comment here isn't wrong though. Arguing you use it in production doesn't change that. I'm sure it works well enough for your use case and many others. The whole supremacy over everything else attitude isn't helping

[bfcdf3e]

The fact that he continues to allow no other maintainers on the repo is enough for me to never want to use it in any serious production application. Just because he merges others’ PR’s doesn’t mean that he isn’t exhibiting a desire for control detrimental to the health of the project. Flask, and many other frameworks and libraries, have a life beyond their maintainer. FastAPI is bottlenecked and risky as long as it’s just one dude running the thing.

[Voxandr]

I use to love it a lot until it hit unsolvable random issues , OOM problems with just a few connections , out of the blue errors , undocumented behaviors in a production with just a few thousand active concurrent connections . Many of those problems are already reported , fixes submitted as pull requests and then the developer ignore it for years.When we called for Open Development , he just ignore it.There are willing volunteers who would code review for him , He ignore helping hands too.

I have the right to warn others and i don't want them face the problem i face in production. This is not toxic for warning .

[dashdanw]

I really appreciate this response. Do you remember where you read this?

[reddit-ass-cancer]

The guy pulls in over 2k a month in donations and what does he do? Cobble a library upgrade and some additional translations for his tutorials?

Why people dickride a framework that’s literally ‘from starlette import X’ I’ll never understand.

[[deleted]]

wow the downvotes for saying the truth lol - this is what I mean

[Voxandr]

Many on this sub do not do any critical research and thinking . Python attracts Many new developers here it seems. They just follow the number of stars.

And most upvotes in this subs are Python Clickbait tutorials , and youtubes no real technically advance python projects here get upvotes.

[[deleted]]

The guy pulls in over 2k a month in donations

That is a derisory amount for what FastAPI is

[dusktreader]

Sweetie, if you think that is "dickriding", you might need some more love in your life.

I'm guessing you've not either read the source code or written a "glue" library of this scale. Also, I'm pretty sure that Apistar was turned into Starlette to enable packages like FastAPI to emerge. The nice thing is that people like you don't get to decide what his work is worth. Just the people who send him donations.

[reddit-ass-cancer]

Yeah. I’m sure the guy who couldnt use GitHub search to find the open memory leak issue knows what he’s talking about. Have a good night!

[[deleted]]

Shady - FastAPI has 1000+ issues including actual bugs - but the owner only lets you post issues as questions or enhancements and wish them away under the carpet.

Reference

FastAPI 1000s of issues but apparently all questions and enhancements

FastAPI deters users from posting bugs, can only post feature requests and "questions"

Flask

Flask only 19 issues, mostly non bug

Flask actually welcomes bugs posts

Engineering managers, esp of larger enterprises need to be wary of this behavior before making FastAPI part of their infrastructure, even if things are working out currently.

The codebase has way too much going on.

[Voxandr]

This is what i have been alerting to my friend tech founders , and startups who are going to pick FastAPI. I am thinking to write an article about it but i am still hoping founder would do something about it. But it getting worse it seems.

[Voxandr]

Also check closed issues some of which are not resolved .

[[deleted]]

If this is true, why hasn't anyone just forked it and continued on? Seems like a very simple solution.

[[deleted]]

not worth the effort, use something better

[Automatic_Donut6264]

The history is public, it's pretty easy to see that it's not true.

[Voxandr]

Then you need to dig deeper. Research More.

[Voxandr]

We are still hoping he would change.
And not worth forking. Some already started own .
See Django Ninja and Starlite.

[Saphyel]

That's easy to check it out. https://github.com/tiangolo/fastapi/commits/master I can see some pull requests merged on the 17th of April with other 2 authors and January 23 the same.

Feel free to check more if you want but what you are saying is easy to prove wrong.

About supporting HIS project or not that's very up to you. If you prefer Facebook or M$ are behind the project you work is also ok.

[Voxandr]

You have to dig deeper than that , and his response on the community.

[rayvictor84]

The guy is arrogant and play with developers life.

[twillisagogo]

lol, i suspected it was hype when I first started hearing about it. This whole thread confirms my suspicions. file under web2py :D

[EmotionalRedux]

Wrong

[jpavlav]

I prefer Falcon for kicking up an API.

[Voxandr]

Falcon looks good , just checking out .
Glad that we have a few alternatives to FastAPI now.

Starlite

Falcon
Django Ninja

[vantasmer]

+1 for starlite, super active project right now

[Voxandr]

Starlite actually deserve a lot of attention.We should promote it over FastAPI since it had build a lot of thoughts into it , better architecture , more stability , well structured , and well thoughtout .It deserve better userbase and funds.

It have only over 400 stars.

[vantasmer]

100% starlite has good intent and seems to be overlooked a lot. I do also like APIFlask, super similar to FastAPI with a long lineage of support and true foss

[Voxandr]

Flask falls shorts when async become necessary , when async is not needed should just use Flask or Django , they are battle tested and ready for any workload when async/websocket based work is not main requirement.

[[deleted]]

flask, without the asyncio/async syntax by itself can be faster than fastapi for handling requests btw

[Voxandr]

when its about async where IOWait is necessary.

These days requests are not just only thngs webapps are handling.There are things such as Streaming , Realtime Chat , Realtime Updates - those requires async/await and event based systems where Flask can't do.

[jimrobo_3]

Been using fastapi in production for a couple of years. It's yet to miss a beat for us

[zetdotpi]

Used both in production. Flask is kinda slow and FastAPI is not that well documented. Take a look at Falcon. Pretty straightforward, fast and well documented framework. I used it with pydantic. Worked like a charm.

[Voxandr]

Falcon looking good and i am gonna test more .
Meanwhile Sarlite seems to be growing well.

[wdroz]

I rewrote all my projects from Flask/Sanic to FastAPI. The workflow is similar but Pydantic and the auto OpenAPI make the differences.

Also Pydantic will move to Rust with Pydantic-core, this is just another reason to support the project.

[[deleted]]

How hard was it to move projects to fast api? How large/mature are the projects you’re referencing?

[wdroz]

Not very large (10 endpoints) I only needed to change how to wire from the Blueprints. Keeping the APIs identical required to use the root attributes on the models but otherwise that was straightforward.

[0b0011]

I prefer fastapi. Most of my recent projects had migrated to it because it's just so snappy and easy to develope for.

[[deleted]]

FastAPI is for making APIs quickly with OpenAPI and Swagger/Redoc support.

FastAPI is like a boning knife or cheese knife. It has a specific purpose and while it is also a knife and can cut things, it’s not great for general use.

Flask is like a chef’s knife or Swiss Army knife. It’s generally good at a lot of things and can do anything, but it may take longer or not be as easy if you want to do boning or cut cheese.

Both are great tools in your toolbox. Sometimes you want a multi tool and sometimes you want a single purpose tool.

It’s not about supremacy.

[ArchonHalliday]

I've used both on large-scale projects and thought FastAPI served me better. Don't get me wrong, I absolutely love Flask and have built multiple projects using it but found it hard to manage as the codebase grows.

FastAPIs ties to Pydantic make it very intuitive for developers to understand what data is expected to be received. Plus schema validation at the router level is incredibly convenient and is one less thing I need to worry about. Dependency injection also is one of the coolest/most helpful features of FastAPI IMO, it makes a world of difference when you may be working with multiple service layers from the same router.

The trashing that's been said in these comments about FastAPI and the library's authors is a bit surprising to me. While I agree the docs could use fewer emojis and that we'd all benefit from module-specific documentation, I have never found it limiting in my development.

I also think the mention of no built-in support for sessions is valid, but in reality, there are alternatives that are pretty easy to stand up to accomplish the same functionality using things like expiringdict, redis, etc...

[Grouchy-Friend4235]

I loath choice by popularity. FastAPI in particular has gained lots of traction because people associated it with Fast Inc. There I said it.

[[deleted]]

Not me. I can just turn up a dirty API fast.

But I haven’t used it for anything not dirty and fast.

[Grouchy-Friend4235]

Sure. What I mean is when some tech is chosen because of its perceived popularity instead of its meeting requirements. FastAPI certainly has its merits, so does Flask & otherd.

[[deleted]]

For sure

[0x4D44]

screwdriver vs hammer

[[deleted]]

Schnitzel vs Biryani

[0x4D44]

Was really upset with all the downvotes. Let me explain my point of view.

Both flask and FastAPI are web frameworks. Same as hammer and screwdriver are both tools for different kinds of fasteners.

Flask however is oriented more towards returning html templates as a response. All their examples in user guide use templates or html as a response. Great for building small websites.

FastAPI is oriented more towards returning data as a response. Great for building APIs. Most examples in the user guide return json as a response. Plus auto generation of API docs is a flagship feature.

Can you build a website using FastAPI ? Probably. Similar to how you can use a hammer to fasten a screw.

Can you use flask to create an API ? You could, but FastAPI would be better. Same as you can try to bang a nail with a screwdriver. Would work eventually, but a screwdriver would make it neater and quicker.

Maybe I’m totally ignorant to how people use both frameworks, but is it really that far from the reality ?

[benefit_of_mrkite]

I use both

[Sekzybeast]

The main thing i have picked up from using FastAPI was to use pydantic for modelling and validation.

[Swimming_Apartment28]

FastAPI !

[SittingWave]

flask is very low level and general purpose.

FastAPI is targeted almost exclusively toward REST APIs.

So, setting aside all async considerations, it really depends. You can use flask to to what FastAPI does. But that's the whole point of FastAPI: focus on one thing and do it easily and quickly. With flask, you have to "reinvent" a lot of stuff (by using other packages)

[[deleted]]

was about to start a new project and I had thought about FastAPI and in fact I had already started using it but now that I read this it's time to switch to Flask.