Express vs. FastAPI vs. Flask vs. Growler Comparison Chart

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.7+ based on standard Python type hints. Fast: Very high performance, on par with NodeJS and Go (thanks to Starlette and Pydantic). One of the fastest Python frameworks available. Minimize code duplication, multiple features from each parameter declaration.

Growler is a web framework built atop asyncio, the asynchronous library described in PEP 3156 and added to the standard library in python 3.4. It takes a cue from the Connect & Express frameworks in the nodejs ecosystem, using a single application object and series of middleware to process HTTP requests. The custom chain of middleware provides an easy way to implement complex applications. The pip utility allows packages to provide optional requirements, so features may be installed only upon request. This meshes well with the minimal nature of the Growler project: don't install anything the user doesn't need. That being said, there are (will be) community packages that are blessed by the growler developers (after ensuring they work as expected and are well tested with each version of growler) that will be available as extras directly from the growler package.