When comparing ASP.NET MVC vs Flask, the Slant community recommends Flask for most people. In the question“What are the best backend web frameworks?” Flask is ranked 4th while ASP.NET MVC is ranked 13th. The most important reason people chose Flask is:
Even though it's pretty minimalistic out of the box, Flask still provides the necessary tools to build a quick prototype for a web app right after a fresh install. With all the main components pretty much packed in the `flask` package, building a simple web app in a single Python file is as easy as it gets.
Ranked in these QuestionsQuestion Ranking
The framework has many build-in tools, and many packages have been written targeting the framework.
Pro Cross platform
.Net Core can work on any platform.
Pro Extensive documentation
There are a lot of resources available to get help.
Pro Widely used
It's pretty easy to find a job with it and there's plenty of documentation and tutorials around.
Pro Asp.NET core provides balance between magic/agility and craftsmanship
You can get ordinary details quickly but with complete freedom to make your craft, knowing everything that is happening underneath the cloths. The highly modular system makes it possible to scale small applications to large ones with ease.
Asp.NET Core on Linux is fast accordingly to TechEmpower benchmarks.
Pro Extremely easy to build a quick prototype
Even though it's pretty minimalistic out of the box, Flask still provides the necessary tools to build a quick prototype for a web app right after a fresh install. With all the main components pretty much packed in the
flask package, building a simple web app in a single Python file is as easy as it gets.
Pro Lots of resources available online
Flask is one of the most popular Python web frameworks, if not the most popular one. As such, there's plenty of guides, tutorials, and libraries available for it. A large number of important Python libraries, such as SQLAlchemy have libraries for Flask, which add valuable bindings to make the development process and the integration between these libraries and Flask as easy as possible.
Pro Minimalist without losing power
Flask is very easy to get up and going, with vanilla HTML or with bootstrap pieces. It doesn't take much lines of Python to load Flask to get headers working, etc, and since it's all modular you don't have to have something you don't want in your application.
Pro Very flexible
Flask gives developers a lot of flexibility in how they develop their web applications.
For example, the choice of not having an ORM, but instead choosing one suited to the task, or another area where Flask gives a lot of options to developers is the templating. They can use Jinja2, Flask's default templating language or choose from a number of different templating languages they desire.
Pro Great documentation
The official documentation is very thorough and complete. Everything is explained in-depth and followed by extremely well-explained tutorials that tackle real-world problems.
Con Not async-friendly
Flask is explicitly not designed to handle async programming.
Con Threadlocals and globals used everywhere
The default way of creating applications in flask makes it hard to use reusable and clean code.
Con Setting up a large project requires some previous knowledge of the framework
Setting up a large project with Flask is not that easy considering how there's no "official" way of doing it. Blueprints are a useful tool in this regard but require some additional reading and are a bit tricky to get right for a beginner.
The lack of some defaults can also be problematic. Having to choose between different libraries for a certain task is never easy, especially if you have never worked with Flask before.