Installing Python FastAPI: A Step-by-Step Guide

Introduction

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints. It's easy to use, fast to develop with, and is built on top of Starlette for the web parts and Pydantic for the data parts.

Step 1: Setting Up Your Environment

First, make sure you have Python 3.6+ installed on your system. You can download Python from python.org.

Step 2: Installing FastAPI

To install FastAPI, you can use pip, Python's package installer. Open your terminal or command prompt and run the following command:

pip install fastapi

This command will install FastAPI and its dependencies.

Step 3: Creating Your First FastAPI Application

Now that FastAPI is installed, let's create a simple example to demonstrate how to use it. Create a new Python file, e.g., main.py, and add the following code:

from fastapi import FastAPI

app = FastAPI()

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

This code creates a FastAPI application with a single route that responds with a JSON message {"message": "Hello, World!"} when you access the root URL.

Step 4: Running Your FastAPI Application

To run your FastAPI application, navigate to the directory containing your main.py file in your terminal or command prompt, and run the following command:

uvicorn main:app --reload

This command starts the Uvicorn server with your FastAPI application, and the --reload flag enables auto-reloading, so you don't need to restart the server every time you make changes to your code.

Once the server is running, you can access your FastAPI application by opening a web browser and navigating to http://localhost:8000. You should see the message {"message": "Hello, World!"} displayed in your browser.

Conclusion

Congratulations! You've successfully installed FastAPI and created your first FastAPI application. You can now start building powerful and efficient APIs with Python using FastAPI.

For more information and advanced usage of FastAPI, check out the FastAPI documentation.