When comparing Bottle vs FastAPI, the Slant community recommends FastAPI for most people. In the question“What are the best backend web frameworks?” FastAPI is ranked 4th while Bottle is ranked 20th. The most important reason people chose FastAPI is:
It has a simple but powerful dependency injection system, it can be used to handle authentication, per-user rate limiting, authorization controls (e.g. with roles), etc.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Flexible
Being a small one file distribution it includes almost every vital thing you need to support little websites (routing, templating). Everything else can be implemented using plugins.
Pro Single-file distribution
Bottle works around the one-file approach, everything is done in a bottle.py
file. This means that it's extremely easy to share and upload your application since it practically is just one python file.
Pro No need to install
It is so little there's no need to install, it is included in the standard libs python.
Pro Async, *let friendly
Using it with gevent is a breeze. It's a WSGI app so it's easy to make it work with anything.
Pro Truly magnificent
Pro Dependency injection
It has a simple but powerful dependency injection system, it can be used to handle authentication, per-user rate limiting, authorization controls (e.g. with roles), etc.
Pro Standards
It is based on standards: OpenAPI, JSON Schema and OAuth 2.0.
Pro Data validation
It validates the data using the types you declared. Even in deeply nested JSON requests.
Pro High-performance
It's based on Starlette and Pydantic, so, it's one of the fastest Python frameworks.
Pro Editor completion
It is based on Python type declarations, so, editors and tools can give great support. Including type checks and autocompletion everywhere.
Pro One of the fastest growing communities
Pro Fast is really fast (!)
It's easy to develop API based applications in Python on deadlines for Android and IOS Development.
Pro Automatic docs
It generates interactive API documentation automatically from your code.
Pro Database independent
It's independent of database or ORM, but compatible with all of them. Including relational databases and NoSQL.
Pro Async IO / optional
It's based on Async IO, which gives it high concurrency. But you can use non-async libraries and it runs them appropriately.
Pro World class documentation
It has some of the best documentation of any framework.
Pro WebSockets
Because it's an async framework, it can handle async-native protocols like WebSockets.
Pro OAuth 2.0
It has integrated support for OAuth 2.0. Including declaring required scopes per endpoint. So, you can easily integrate it with external OAuth 2.0 providers or build your own with it.
Pro Background tasks
Included support for background tasks, thanks to being based on Starlette.
Pro Supports GraphQL
Python's graphene library is included as an optional dependency meaning that GraphQL API's are supported out of the box, with no additional tweaking needed.
Cons
Con Small community. Difficult to find online docs and examples
Con Very hard to develop projects that are not smaller than 1000 lines
While Bottle is a great framework for building small applications (generally less than 1000 lines of code), it starts getting very hard to manage your application if you want to go even a bit larger than that.
The fact that it follows a single-file distribution model and that it's missing something like Flask's blueprints only make this problem worse.
Con Smaller community
Since FastAPI is relatively new, its community is smaller than Django Rest Framework. But it can grow with time.