Parameters

At this stage, you should have a well-structured base project and a database configured with a table to keep blog post records.

Before writing code, it's worth understanding the difference between Path Parameters and Query Parameters.

Path Parameters

Path parameters are parameters that get included in the context path of a URL. For example, the unique ID of each blog post gets appended to the URL providing a link to individual posts.

https://www.exampleforyou.net/blog/963e4ca9-2080-4f15-93ba-a8509bb63f6b

So a corresponding function would be matched, and can utilize the value 963e4ca9-2080-4f15-93ba-a8509bb63f6b which becomes id from {id}, for example:

@router.get('/blog/{id}'...
def get_blogpost(*, id: UUID...

Query Parameters

A query a parameter is a key/value pair appended to a URL after a ?, for example:

https://www.exampleforyou.net/api/v1/blog?limit=2

So the corresponding function doesn't have any defined {} parameter in the path, but the function does expect an incoming value, in this case limit. (The syntax | None = None is new since Python 3.10):

@router.get('/blog'...
def get_blogposts(limit: int | None = None...

Keep this in mind when working through the upcoming CRUD examples.