Query Parameters

A classical method of passing the request data to the server is to append a query string to the URL. Assuming that a Python script (hello.py) on a server is executed as CGI, a list of key-value pairs concatenated by the ampersand (&) forms the query string, which is appended to the URL by putting a question mark (?) as a separator. For example −

http://localhost/cgi-bin/hello.py?name=Ravi&age=20

The trailing part of the URL, after (?), is the query string, which is then parsed by the server-side script for further processing.

As mentioned, the query string is a list of parameter=value pairs concatenated by & symbol. FastAPI automatically treats the part of the endpoint which is not a path parameter as a query string and parses it into parameters and its values. These parameters are passed to the function below the operation decorator.