!!! note "Hinweis"
    Wenn Sie ein Python-Experte sind und bereits alles über Typhinweise wissen, überspringen Sie dieses Kapitel und fahren Sie mit dem nächsten fort.

## Motivation

Fangen wir mit einem einfachen Beispiel an:

```Python
{!../../../docs_src/python_types/tutorial001.py!}
```

Dieses Programm gibt aus:

```
John Doe
```

Die Funktion macht Folgendes:

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

!!! note
    If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

## Motivation

Let's start with a simple example:

```Python
{!../../../docs_src/python_types/tutorial001.py!}
```

Calling this program outputs:

```
John Doe
```

The function does the following:

    @Override
    public boolean isActive(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        Activation activation = profile.getActivation();

        if (activation == null) {
            return false;
        }

        ActivationFile file = activation.getFile();

        if (file == null) {
            return false;
        }

        String path;
        boolean missing;

    @Override
    public boolean presentInConfig(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        Activation activation = profile.getActivation();

        if (activation == null) {
            return false;
        }

        ActivationProperty property = activation.getProperty();

        return property != null;
    }

    @Override
    public boolean isActive(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        Activation activation = profile.getActivation();

        if (activation == null) {
            return false;
        }

        String jdk = activation.getJdk();

        if (jdk == null) {
            return false;
        }

    @Override
    public boolean isActive(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
        Activation activation = profile.getActivation();

        if (activation == null) {
            return false;
        }

        ActivationOS os = activation.getOs();

        if (os == null) {
            return false;
        }

        boolean active = ensureAtLeastOneNonNull(os);

import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;

import org.apache.maven.api.services.model.*;

/**
 * Describes the environmental context used to determine the activation status of profiles.
 *
 */
public class DefaultProfileActivationContext implements ProfileActivationContext {

    private List<String> activeProfileIds = Collections.emptyList();

    /**
     * Determines the profiles which are active in the specified activation context. Active profiles will eventually be
     * injected into the model.
     *
     * @param profiles The profiles whose activation status should be determined, must not be {@code null}.
     * @param context The environmental context used to determine the activation status of a profile, must not be
     *            {@code null}.

import org.apache.maven.api.di.Singleton;
import org.apache.maven.api.model.Activation;
import org.apache.maven.api.model.Profile;
import org.apache.maven.api.services.ModelProblemCollector;
import org.apache.maven.api.services.model.ProfileActivationContext;
import org.apache.maven.api.services.model.ProfileActivator;

/**
 * Determines profile activation based on the project's packaging.
 */
@Named("packaging")
@Singleton

        for (int index = 0; index < profiles.size(); index++) {
            Profile profile = profiles.get(index);
            Activation activation = profile.getActivation();
            if (activation != null) {
                ActivationFile file = activation.getFile();
                if (file != null) {
                    String oldExists = file.getExists();
                    if (isNotEmpty(oldExists)) {