Pero antes de eso, manejar el código asíncrono era mucho más complejo y difícil.

En versiones previas de Python, podrías haber usado hilos o <a href="https://www.gevent.org/" class="external-link" target="_blank">Gevent</a>. Pero el código es mucho más complejo de entender, depurar y razonar.

En versiones previas de NodeJS / JavaScript en el Navegador, habrías usado "callbacks". Lo que lleva al "callback hell".

 *       unnecessary; for example, {@code copyOf(copyOf(anArrayList))} should copy the data only
 *       once. This reduces the expense of habitually making defensive copies at API boundaries.
 *       However, the precise conditions for skipping the copy operation are undefined.
 *   <li><b>Warning:</b> a view collection such as {@link ImmutableMap#keySet} or {@link

Você também pode defini-la como uma função normal em vez de `async def`:

{* ../../docs_src/first_steps/tutorial003_py39.py hl[7] *}

/// note | Nota

Se você não sabe a diferença, verifique o [Async: *"Com pressa?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

### Passo 5: retorne o conteúdo { #step-5-return-the-content }

{* ../../docs_src/first_steps/tutorial001_py39.py hl[8] *}

     * manage that 4 byte header specifically and therefore the initial
     * bufferIndex, and thus headerStart, would be 4).(NOTE: If one where
     * looking for a way to improve perfomance this is precisly what you
     * would want to do as the jcifs.smb1.netbios.SocketXxxputStream classes
     * arraycopy all data read or written into a new buffer shifted over 4!)
     */

    byte command, flags;

      }
    }
    return true;
  }

  /**
   * Modifies {@code multisetToModify} so that its count for an element {@code e} is at most {@code
   * multisetToRetain.count(e)}.
   *
   * <p>To be precise, {@code multisetToModify.count(e)} is set to {@code
   * Math.min(multisetToModify.count(e), multisetToRetain.count(e))}. This is similar to {@link

      }
    }
    return true;
  }

  /**
   * Modifies {@code multisetToModify} so that its count for an element {@code e} is at most {@code
   * multisetToRetain.count(e)}.
   *
   * <p>To be precise, {@code multisetToModify.count(e)} is set to {@code
   * Math.min(multisetToModify.count(e), multisetToRetain.count(e))}. This is similar to {@link

Das bedeutet:

* Die Variable `prices` ist ein `dict`:
    * Die Schlüssel dieses `dict` sind vom Typ `str` (z. B. die Namen der einzelnen Artikel).
    * Die Werte dieses `dict` sind vom Typ `float` (z. B. der Preis jedes Artikels).

#### <abbr title="Union – Verbund, Einheit‚ Vereinigung: Eines von Mehreren">Union</abbr> { #union }

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

**Nota**:

Se você não sabe, verifique a seção _"Com pressa?"_ sobre <a href="https://fastapi.tiangolo.com/pt/async/#in-a-hurry" target="_blank">`async` e `await` nas docs</a>.

</details>

### Rode { #run-it }

Rode o servidor com:

<div class="termy">

      }
    };
  }

  // Methods only in Iterables, not in Iterators

  /**
   * Determines if the given iterable contains no elements.
   *
   * <p>There is no precise {@link Iterator} equivalent to this method, since one can only ask an
   * iterator whether it has any elements <i>remaining</i> (which one does using {@link
   * Iterator#hasNext}).
   *

published by Affero, was designed to accomplish similar goals.  This is
a different license, not a version of the Affero GPL, but Affero has
released a new version of the Affero GPL which permits relicensing under
this license.

  The precise terms and conditions for copying, distribution and
modification follow.

                       TERMS AND CONDITIONS

  0. Definitions.

  "This License" refers to version 3 of the GNU Affero General Public License.