# specifically. Use your best judgment to keep the scripts in this directory
# lean and easy to follow. When in doubt, remember that for CI scripts, "keep it
# simple" is MUCH more important than "don't repeat yourself."

# -e: abort script if one command fails
# -u: error if undefined variable used
# -x: log all commands
# -o pipefail: entire command fails if pipe fails. watch out for yes | ...

    * FastAPI apporte des fonctionnalités supplémentaires à Starlette. Des fonctionnalités dont vous avez presque toujours besoin lors de la création d'une API, comme la validation des données et la sérialisation. En l'utilisant, vous obtenez une documentation automatique « gratuitement » (la documentation automatique n'ajoute même pas de surcharge...

			newBuf := make([]byte, newSize)
			copy(newBuf, s.buf[s.start:s.end])
			s.buf = newBuf
			s.end -= s.start
			s.start = 0
		}
		// Finally we can read some input. Make sure we don't get stuck with
		// a misbehaving Reader. Officially we don't need to do this, but let's
		// be extra careful: Scanner is for safe, simple jobs.
		for loop := 0; ; {
			n, err := s.r.Read(s.buf[s.end:len(s.buf)])
			if n < 0 || len(s.buf)-s.end < n {

Vous êtes libre de les utiliser comme vous le souhaitez, **FastAPI** n’impose aucune restriction.

Mais ce guide vous montre, plus ou moins, la façon dont ils sont censés être utilisés.

///

### Utiliser le paramètre `exclude_unset` de Pydantic { #using-pydantics-exclude-unset-parameter }

In the previous example, because the classes were different, we had to use the `response_model` parameter. But that also means that we don't get the support from the editor and tools checking the function return type.

But in most of the cases where we need to do something like this, we want the model just to **filter/remove** some of the data as in this example.

    return {"Hello": "World"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: str | None = None):
    return {"item_id": item_id, "q": q}
```

**Note**:

If you don't know, check the _"In a hurry?"_ section about [`async` and `await` in the docs](https://fastapi.tiangolo.com/async/#in-a-hurry).

</details>

### Run it

Run the server with:

<div class="termy">

## Dependencies with `yield` and `except` { #dependencies-with-yield-and-except }

If you catch an exception using `except` in a dependency with `yield` and you don't raise it again (or raise a new exception), FastAPI won't be able to notice there was an exception, the same way that would happen with regular Python:

{* ../../docs_src/dependencies/tutorial008c_an_py310.py hl[15:16] *}

	if extractedExpect != expectedExpect {
		t.Errorf("expect header incorrect value: expected `%s`, got `%s`", expectedExpect, extractedExpect)
	}

	// case where the headers don't contain the one of the signed header in the signed headers list.
	signedHeaders = append(signedHeaders, "X-Amz-Credential")
	// expected to fail with `ErrUnsignedHeaders`.
	_, errCode = extractSignedHeaders(signedHeaders, r)

        return existingTask.latch
      }
      for (futureTask in futureTasks) {
        if (futureTask is AwaitIdleTask) {
          return futureTask.latch
        }
      }

      // Don't delegate to schedule() because that enforces shutdown rules.
      val newTask = AwaitIdleTask()
      if (scheduleAndDecide(newTask, 0L, recurrence = false)) {
        taskRunner.kickCoordinator(this)
      }

                            main.getVersion(),
                            main.getProperties(),
                            main.getPath()));
                }
                // If deployBuildPom is false, we simply don't add the build POM to the result
            }
            for (Artifact consumer : consumers) {
                result.remove(consumer);
                // Replace the consumer POM as the main POM (no classifier)