{* ../../docs_src/path_params/tutorial001.py hl[6:7] *}

O valor do parâmetro que foi passado à `item_id` será passado para a sua função como o argumento `item_id`.

Então, se você rodar este exemplo e for até <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, você verá a seguinte resposta:

```JSON

Mehr erfahren Sie am Ende dieser Seite.

///

## Zusätzliche Argumente für `Field`

Wenn Sie `Field()` mit Pydantic-Modellen verwenden, können Sie ebenfalls zusätzliche `examples` deklarieren:

{* ../../docs_src/schema_extra_example/tutorial002_py310.py hl[2,8:11] *}

// [Writer.CreateHeader], [Writer.CreateRaw], or [Writer.Close].
//
// In contrast to [Writer.CreateHeader], the bytes passed to Writer are not compressed.
//
// CreateRaw's argument is stored in w. If the argument is a pointer to the embedded
// [FileHeader] in a [File] obtained from a [Reader] created from in-memory data,
// then w will refer to all of that memory.

{* ../../docs_src/path_params/tutorial001.py hl[6:7] *}

Der Wert des Pfad-Parameters `item_id` wird Ihrer Funktion als das Argument `item_id` übergeben.

Wenn Sie dieses Beispiel ausführen und auf <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> gehen, sehen Sie als Response:

```JSON

 # endif
 #endif
 
+/* Undefine (also defined in libc-symbols.h).  */
+#undef __attribute_copy__
+#if __GNUC_PREREQ (9, 0)
+/* Copies attributes from the declaration or type referenced by
+   the argument.  */
+# define __attribute_copy__(arg) __attribute__ ((__copy__ (arg)))
+#else
+# define __attribute_copy__(arg)
+#endif
+
 #endif	 /* sys/cdefs.h */
diff --git a/stdlib/setenv.c b/stdlib/setenv.c

{* ../../docs_src/path_params/tutorial001.py hl[6:7] *}

El valor del parámetro de path `item_id` se pasará a tu función como el argumento `item_id`.

Así que, si ejecutas este ejemplo y vas a <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, verás un response de:

```JSON
{"item_id":"foo"}

Por ejemplo, podrías tener un archivo `main.py` con:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | Consejo

El segundo argumento de <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> es el valor por defecto a retornar.

   * function for most uses, but the virtualized form is needed within retryUpdate.
   *
   * @param currentValue the current value (of either base or a cell)
   * @param newValue the argument from a user update call
   * @return result of the update function
   */
  abstract long fn(long currentValue, long newValue);

  /**

    String ancestorName = name.substring(substringFrom);

    return new InternetDomainName(ancestorName, ancestorParts);
  }

  /**
   * Creates and returns a new {@code InternetDomainName} by prepending the argument and a dot to
   * the current name. For example, {@code InternetDomainName.from("foo.com").child("www.bar")}
   * returns a new {@code InternetDomainName} with the value {@code www.bar.foo.com}. Only lenient

   * reached the {@linkplain State#RUNNING running} state.
   *
   * @param timeout the maximum time to wait
   * @param unit the time unit of the timeout argument
   * @throws TimeoutException if not all of the services have finished starting within the deadline
   * @throws IllegalStateException if the service manager reaches a state from which it cannot