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FASTAPI: A Simple Guide with Installation Steps

Arjun JS , ,

FASTAPI is a modern, fast (high-performance), web framework for building APIs with Python. It is known for its simplicity, scalability, and speed. In this article, we will walk you through the installation process and provide a basic understanding of how to get started with FASTAPI.

Installation Steps

To begin with FASTAPI, you need to have Python installed on your system. Make sure you have Python 3.7 or above version installed. Follow these steps to install FASTAPI:

Step 1: Create a Virtual Environment (Optional)

Creating a virtual environment is optional but recommended to keep your project dependencies isolated. Open your terminal and run the following command:

python3 -m venv myenv

Replace “myenv” with the name you want to give your virtual environment.

Step 2: Activate the Virtual Environment

Activate the virtual environment you just created. On Windows, run the following command:

myenv\Scripts\activate

On macOS or Linux, run:

source myenv/bin/activate

Step 3: Install FASTAPI

Once your virtual environment is active, you can install FASTAPI and its dependencies using the following command:

pip install fastapi

Step 4: Install an ASGI Server (Optional)

FASTAPI is built on top of ASGI (Asynchronous Server Gateway Interface). While FASTAPI comes with a built-in development server, you may need to install an ASGI server for production deployment. One popular choice is Uvicorn. Install Uvicorn by running:

pip install uvicorn

Your First FASTAPI Application

Now that you have FASTAPI installed, let’s create a simple “Hello, World!” application using FASTAPI.

Step 1: Create a new Python file

Create a new Python file called main.py and open it in your favorite text editor.

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Step 2: Import FASTAPI

In main.py, import the necessary modules by adding the following lines at the top of the file:

from fastapi import FastAPI

Step 3: Create an instance of FastAPI

Next, create an instance of the FastAPI class by adding the following code:

app = FastAPI()

Step 4: Define a route and handler

Add a route to your application by defining a function that will handle the request. For a “Hello, World!” example, add the following code:

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

This code sets up a route for the root URL (“/”) and returns a JSON response with the message “Hello, World!”.

Step 5: Run the application

Save the main.py file and go back to your terminal. Make sure your virtual environment is still active, then run the following command:

uvicorn main:app --reload

This command starts the Uvicorn server and reloads the application whenever changes are detected.

Step 6: Test your application

Open your web browser and visit http://localhost:8000 (or http://localhost:8000/docs for the Swagger UI). You should see the “Hello, World!” message displayed.

Congratulations! You have successfully created a basic FASTAPI application.

Conclusion

In this article, we covered the installation process for FASTAPI and created a simple “Hello, World!” application. FASTAPI’s simplicity, performance, and powerful features make it an excellent choice for building APIs in Python. With this foundation, you

can now explore the extensive documentation and build more complex applications using FASTAPI.

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