High-Performing Web Framework for Building APIs using FastAPI

Introduction to FastAPI

FastAPI is a Python based framework that has a collection of tools that let programmers use frequently used functions using a REST interface to create apps. It can be called by using a REST API, which is a common building piece for apps.

This framework is made to enhance our developer experience so that we can write straightforward code to create production-ready APIs.

Features of Fast API

Simple:

• It’s created to be simple to use and learn, saving our time from having to read manuals.
• It enables huge increases in development time and is quick to code.
• It reduces code duplication, in brief.

Runs quickly:

• Starlette and pydantic libraries provide FastAPI performance that is on par with NodeJS and Go.

Robust:

• It offers production-ready code with interactive documentation that is generated automatically.
• It is built on OpenAPI and JSON Schema, two open standards for APIs.

FastAPI Vs Flask

• Recently, FastAPI has attracted a lot of interest. Flask and its development structure are extremely similar to FastAPI.
• Python web servers and data science programs can be swiftly set up using Flask and FastAPI. When it comes to deployment, they both demand the same amount of work.
• When speed and performance are crucial, FastAPI is the best option. Choose this more recent framework if you’re creating your CDN and anticipate heavy traffic. With FastAPI, you can simply download and use the framework that is already developed on cutting-edge technology while also enjoying the time-saving benefits of the project template.
• FastAPI will be a better option when you’re constructing APIs than Flask, especially when microservices are taken into account. The only justification for using Flask in this situation would be if your company already has a substantial amount of tooling based on that framework.
• When you need to create a straightforward microservice with a few API endpoints, pick Flask instead. It’s also a fantastic choice for developing data-driven web application prototypes and machine learning models.

Installing Fast API

It is very easy to install FastAPI with the below command:

Now that FastAPI and Uvicorn are set up, you are prepared to start exploring how to use them. Your API will be built using the FastAPI framework, and Uvicorn will be the server that processes requests using your built-in API.

Steps to Create App in FastAPI

1. Create a folder with Python venv and activate the venv using the below commands:

2. Install FastAPI and Uvicorn in venv

3. Create a main.py file in the venv Scripts folder with the below code

4. Enter the below command with the filename “main” to start the server.

You can refer to the below output in the terminal.

Hit the localhost URL to see the response in the browser.

Explanation:

1. We create a FastAPI app object, a Python class that contains all the features your API needs.
2. To organize our API endpoints, we instantiate an APIRouter
3. We define a fundamental GET endpoint for our API by adding the @api router.get(“/”, status code=200) decorator to the root function.
4. The router we constructed in step 2 is registered on the FastAPI object using the included router method of the app object.

Example with Path Parameters:

The below code shows how API routing is done with parameters in the URL path.

Try out your endpoint:

You will see automatic, interactive API documentation when you launch your browser at http://127.0.0.1:8000/docs.

• Clicking on the GET endpoint will expand it.
• Select “Try It Out” from the menu.
• Click the “Execute” button.
• Select the “Execute” button.

Conclusion

In this blog, we have gone through the main features of FastAPI and discussed the Flask framework vs the FastAPI framework. We created our first app in FastAPI and went through different path parameters. We have used the app.get method in our code, similarly in the app route we can use all the REST methods.

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