## Variáveis de Ambiente

/// tip | Dica

Se você já sabe o que são variáveis de ambiente e como utilizá-las, sinta-se livre para avançar para o próximo tópico.

///

/**
 * A {@link Table} whose contents will never change, with many other important properties detailed
 * at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Gregory Kick
 * @since 11.0
 */
@GwtCompatible
public abstract class ImmutableTable<R, C, V> extends AbstractTable<R, C, V>

* <a href="https://pythonhosted.org/itsdangerous/" target="_blank"><code>itsdangerous</code></a> - Обязательно, для поддержки `SessionMiddleware`.
* <a href="https://pyyaml.org/wiki/PyYAMLDocumentation" target="_blank"><code>pyyaml</code></a> - Обязательно, для поддержки `SchemaGenerator` Starlette (возможно, вам это не нужно с FastAPI).

Используется FastAPI / Starlette:

 * in a way that affects its {@link Object#equals} behavior. Undefined behavior and bugs will
 * result.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible

</div>

///

この情報は、[Virtual Environments](virtual-environments.md) について学ぶ際にも役立ちます。

## まとめ

これで、**環境変数**とは何か、Pythonでどのように使用するかについて、基本的な理解が得られたはずです。

環境変数についての詳細は、<a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">Wikipedia: Environment Variable</a> を参照してください。

環境変数の用途や適用方法が最初は直感的ではないかもしれませんが、開発中のさまざまなシナリオで繰り返し登場します。そのため、基本を知っておくことが重要です。

 * consecutively when iterating. Elements iterate in order by the <i>first</i> appearance of that
 * element when the multiset was created.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization

 * {@code Multiset}, {@code AtomicLongMap} does not automatically remove zeros.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multiset">{@code Multiset}</a>.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public interface Multiset<E extends @Nullable Object> extends Collection<E> {

* <a href="https://pythonhosted.org/itsdangerous/" target="_blank"><code>itsdangerous</code></a> - `SessionMiddleware` dəstəyi üçün tələb olunur.
* <a href="https://pyyaml.org/wiki/PyYAMLDocumentation" target="_blank"><code>pyyaml</code></a> - `SchemaGenerator` dəstəyi üçün tələb olunur (Çox güman ki, FastAPI istifadə edərkən buna ehtiyacınız olmayacaq).

 *
 * <p>This implementation guarantees insertion-based iteration order of its keys.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#bimap">{@code BiMap} </a>.
 *
 * @author Louis Wasserman
 * @author Mike Bostock
 * @since 2.0
 */
@GwtCompatible

   *
   * (The index actually stored is the index of the key in alternatingKeysAndValues, which is
   * double the index of the entry in entrySet.asList.)
   *
   * The basic data structure is described in https://en.wikipedia.org/wiki/Open_addressing.
   * The pointer to a key is stored in hashTable[Hashing.smear(key.hashCode()) % table.length],
   * save that if that location is already full, we try the next index, and the next, until we