Now, get the user data from the (fake) database, using the `username` from the form field.

If there is no such user, we return an error saying "Incorrect username or password".

For the error, we use the exception `HTTPException`:

=== "Python 3.10+"

    ```Python hl_lines="3  79-81"
    {!> ../../../docs_src/security/tutorial003_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="3  79-81"