* <a href="https://fastapi.tiangolo.com/tutorial/bigger-applications/" class="external-link" target="_blank">Tutorial - Bigger Applications</a>.

No identifier may be declared twice in the same block, and
no identifier may be declared in both the file and package block.
</p>

<p>
The <a href="#Blank_identifier">blank identifier</a> may be used like any other identifier
in a declaration, but it does not introduce a binding and thus is not declared.
In the package block, the identifier <code>init</code> may only be used for