Category: Fast API

Mix Path, Query and body parameters¶ First, of course, you can mix Path, Query and request body parameter declarations freely and FastAPI will know what to do. Note Notice that, in this case, the item that would be taken from the body is optional. As it has a None default value. Multiple body parameters¶ In the previous example, the path operations would expect a JSON body with the attributes…

In the same way that you can declare more validations and metadata for query parameters with Query, you can declare the same type of validations and metadata for path parameters with Path. Import Path Info FastAPI added support for Annotated (and started recommending it) in version 0.95.0. If you have an older version, you would get errors when trying…

FastAPI allows you to declare additional information and validation for your parameters. The query parameter q is of type Union[str, None] (or str | None in Python 3.10), that means that it’s of type str but could also be None, and indeed, the default value is None, so FastAPI will know it’s not required. Note FastAPI will know that the value of q is not required because of…

When you need to send data from a client (let’s say, a browser) to your API, you send it as a request body. A request body is data sent by the client to your API. A response body is the data your API sends to the client. Your API almost always has to send a response body. But clients don’t necessarily need…

The query is the set of key-value pairs that go after the ? in a URL, separated by & characters. For example, in the URL:http://127.0.0.1:8000/items/?skip=0&limit=10 …the query parameters are: As they are part of the URL, they are “naturally” strings. But when you declare them with Python types (in the example above, as int), they are converted to that type…

The value of the path parameter item_id will be passed to your function as the argument item_id. So, if you run this example and go to http://127.0.0.1:8000/items/foo, you will see a response of:{“item_id”:”foo”} Path parameters with types¶ In this case, item_id is declared to be an int. Check This will give you editor support inside of your function, with error checks, completion,…

Copy that to a file main.py. Run the live server: Note The command uvicorn main:app refers to: That line shows the URL where your app is being served, in your local machine. Check it¶ Open your browser at http://127.0.0.1:8000. You will see the JSON response as:{“message”: “Hello World”} Interactive API docs¶ Now go to http://127.0.0.1:8000/docs. You will see the automatic…

This tutorial shows you how to use FastAPI with most of its features, step by step. Each section gradually builds on the previous ones, but it’s structured to separate topics, so that you can go directly to any specific one to solve your specific API needs. It is also built to work as a future reference. So…