Yeah I feel FastAPI will become the new Flask in a few years. The growth this ye...

Scarbutt · on Sept 13, 2019

Yeah I feel FastAPI will become the new Flask in a few years.

What else does it offers besides performance (switching to async is no free lunch)?

acemarke · on Sept 13, 2019

I ran across FastAPI earlier this year and did a tiny prototype to play with it. Selling points for me:

- Integrates nicely with some existing libraries (Starlette, Pydantic)

- Well documented

- Auto-validation of endpoints from data models

- Auto-generation of OpenAPI schemas from those models

- Auto-serves live API docs from that schema

- Easy definition of sync and async endpoints

Again, it was just a tiny proof-of-concept prototype, but I'm sold on using it on future projects.

hyzyla · on Sept 14, 2019

But I found one drawback of using FastAPI - defining all inputs in handler function signature is looks bit complicated and verbose. I prefer one input with type that are structure of another types. Something like this:

  class CreatePostInput(InputClass):
       text: str
       user_id: str
       ...
  
  @handler.post('/post')
  def create_post(input: CreatePostInput):
      ...

ivalm · on Sept 14, 2019

> - Auto-generation of OpenAPI schemas from those models

Is there a package that can do a reverse? Can I give it an OpenAPI spec and get a code stump going?

BerislavLopac · on Sept 14, 2019

OpenAPI-generator [0], written in Java, can produce Python stumps, but I never liked that approach.

Connexion [1] is built on top on Flask and does routing and validation based on an OpenAPI spec.

I've recently started developing Pyotr [2], which does the same only based on ASGI and Starlette. It also includes a client module.

[0] https://openapi-generator.tech/

[1] https://connexion.readthedocs.io/

[2] https://github.com/berislavlopac/pyotr

drchaim · on Sept 14, 2019

https://github.com/zalando/connexion/

Solves most of the problems for that.

rvdmei · on Sept 14, 2019

Depends on where you are coming from and what you need. Developer productivity is really high (real world experience). It has better defaults / builtins compared to flask (much faster to get to production quality). Faster to learn than Django / Django rest framework. My team has been using it for a couple of months now and it’s been really easy and fast to get an API up and running with api docs, data validation, middleware for auth and metrics, persistence, mix of async and sync functions and background jobs.