Quick Guide to Fast API: A Simplified Approach

FastAPI is a modern web framework for building APIs with Python that is designed to be fast, easy, and efficient. In this crash course, we will cover the basics of FastAPI and how you can quickly get started with building your own APIs.

Installing FastAPI
To get started with FastAPI, you will first need to install it. You can do this using pip by running the following command:

pip install fastapi

You will also need to install an ASGI server to run your FastAPI application. For this tutorial, we will be using uvicorn as our ASGI server. You can install it by running:

pip install uvicorn

Creating a FastAPI application
Once you have FastAPI installed, you can create a new FastAPI application by creating a new Python file and importing the FastAPI class. You can then create a FastAPI instance like so:

from fastapi import FastAPI

app = FastAPI()

Defining routes
In FastAPI, routes are defined using decorator functions. You can define a route by using the @app.get or @app.post decorator followed by the path for the route. For example, to define a simple GET route that returns "Hello, World!", you can do the following:

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

In this example, the @app.get("/") decorator defines a route for the root path ("/") that will return a JSON response with the message "Hello, World!".

Running the FastAPI application
To run your FastAPI application, you can use the uvicorn command-line tool. Simply run the following command in the same directory as your FastAPI application file:

uvicorn filename:app --reload

Replace filename with the name of your Python file. The --reload flag will automatically reload the server when changes are made to your code.

Accessing your FastAPI application
Once you have your FastAPI application running, you can access it by navigating to http://127.0.0.1:8000 in your web browser. You should see the "Hello, World!" message returned from the defined route.

Adding request parameters
You can also define routes that accept request parameters in FastAPI. For example, you can define a route that accepts a name parameter and returns a custom message with that name like so:

@app.get("/hello/{name}")
def hello_name(name: str):
    return {"message": f"Hello, {name}!"}

In this example, the name parameter is passed in the route path and accessed as a function parameter. The route will return a custom message that includes the provided name.

Conclusion
This crash course has covered the basics of FastAPI and how you can quickly get started with building your own APIs. FastAPI provides a modern and efficient framework for building APIs with Python, and its simplicity and speed make it an excellent choice for developers looking to quickly create high-performance APIs.

I hope this crash course has been helpful in getting you started with FastAPI and that you are excited to explore more of what this powerful framework has to offer. Happy coding!