Is FastAPI better than Flask?

Comparison of FastAPI and Flask frameworks

Introduction

FastAPI and Flask are web frameworks for python web development. These provide the basic tools for building a web application, including a development server, a routing system, and support for template rendering.

Flask

Flask is a microframework for Python web development. It provides the basic tools for building a web application, including a development server, a routing system, and support for template rendering. Flask is a good choice for small, simple applications, or for those who want a lightweight framework that is easy to learn and customize.

To use Flask, you will need to install it first. You can do this using pip:

pip install Flask

Once Flask is installed, you can create a new Flask app by creating a new Python file and importing the Flask class:

from flask import Flask
app = Flask(__name__)

Next, you can define route handlers, which are functions that are called when a client makes a request to a specific URL. These route handlers are decorated with the @app.route decorator:

@app.route('/')
def hello():
    return 'Hello, World!'

Finally, you can start the development server by calling the run method on the app object:

if __name__ == '__main__':
    app.run()

This will start the Flask development server, which you can access by visiting http://127.0.0.1:5000/ in your web browser. The “Hello, World!” message that you defined in the route handler will be displayed on the page.

Here is a complete “Hello, World!” program in Flask:

from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello():
    return 'Hello, World!'
if __name__ == '__main__':
    app.run()

Overall, Flask is a simple and lightweight framework that is easy to learn and customize. It is a good choice for small, simple web applications

FastAPI

FastAPI is a modern, high-performance framework for building APIs with Python. It is built on top of the popular Python asyncio library, which makes it easy to build asynchronous, high-concurrency applications. FastAPI includes many features out-of-the-box that are not included in other frameworks, such as automatic validation of request data and automatic generation of OpenAPI documentation.

To use FastAPI, you will need to install it first. You can do this using pip:

pip install fastapi

Once FastAPI is installed, you can create a new FastAPI app by importing the FastAPI class and creating a new instance of it:

from fastapi import FastAPI

app = FastAPI()

Next, you can define route handlers, which are functions that are called when a client makes a request to a specific URL. These route handlers are decorated with the @app.get or @app.post decorators, depending on the HTTP method of the request:

@app.get('/')
def hello():
    return {'message': 'Hello, World!'}

Finally, you can start the development server by running the Python file that contains your FastAPI app:

if __name__ == '__main__':
    uvicorn.run(app, host='127.0.0.1', port=8000)

This will start the FastAPI development server, which you can access by visiting http://127.0.0.1:8000/ in your web browser. The “Hello, World!” message that you defined in the route handler will be displayed on the page.

Here is a complete “Hello, World!” program in FastAPI:

from fastapi import FastAPI

app = FastAPI()
@app.get('/')
def hello():
    return {'message': 'Hello, World!'}

if __name__ == '__main__':
    uvicorn.run(app, host='127.0.0.1', port=8000)

Overall, FastAPI is a powerful, modern framework for building APIs with Python. Its use of the asyncio library makes it highly performant, and its built-in features make it easy to develop APIs quickly and easily.

Key differences between Flask and FastAPI:

• Performance: FastAPI is built on top of the Python asyncio library, which makes it highly performant. Flask, on the other hand, is not asynchronous by default, so it may not be as performant for certain types of applications.
• Features: FastAPI includes many features out-of-the-box that are not included in Flask, such as automatic validation of request data and automatic generation of OpenAPI documentation. Flask, on the other hand, is more bare-bones and requires you to add these features yourself.
• Learning curve: Flask is a simple, easy-to-learn framework, making it a good choice for those who are new to web development. FastAPI, on the other hand, is more complex and may have a steeper learning curve.
• Community: Flask has been around longer and has a larger community, so there is more support and resources available for it. FastAPI is a newer framework and has a growing community, but it may not have as much support and resources available at the moment.
• Use cases: Flask is a good choice for small, simple web applications, while FastAPI is better suited for building APIs and high-performance, asynchronous web applications.

Conclusion:

Flask is a good choice for small, simple applications, or for those who want a lightweight framework that is easy to learn and customize. FastAPI, on the other hand, is a better choice for larger, more complex applications, or for those who need a high-performance framework for building APIs. FastAPI is also built on top of the popular Python asyncio library, which makes it easy to build asynchronous, high-concurrency applications.

Overall, the choice between Flask and FastAPI will depend on your specific needs and requirements. If you want a simple, easy-to-use framework, Flask may be the right choice for you. If you need a more powerful, high-performance framework for building APIs, FastAPI may be a better option.