

文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 [AWS SDK 範例](https://github.com/awsdocs/aws-doc-sdk-examples)。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 使用 SDK for Python (Boto3) 的 Amazon Comprehend 範例
<a name="python_3_comprehend_code_examples"></a>

下列程式碼範例示範如何使用 適用於 Python (Boto3) 的 AWS SDK 搭配 Amazon Comprehend 執行動作和實作常見案例。

*Actions* 是大型程式的程式碼摘錄，必須在內容中執行。雖然動作會告訴您如何呼叫個別服務函數，但您可以在其相關情境中查看內容中的動作。

*案例*是向您展示如何呼叫服務中的多個函數或與其他 AWS 服務組合來完成特定任務的程式碼範例。

每個範例均包含完整原始碼的連結，您可在連結中找到如何設定和執行內容中程式碼的相關指示。

**Topics**
+ [動作](#actions)
+ [案例](#scenarios)

## 動作
<a name="actions"></a>

### `CreateDocumentClassifier`
<a name="comprehend_CreateDocumentClassifier_python_3_topic"></a>

以下程式碼範例顯示如何使用 `CreateDocumentClassifier`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def create(
        self,
        name,
        language_code,
        training_bucket,
        training_key,
        data_access_role_arn,
        mode,
    ):
        """
        Creates a custom classifier. After the classifier is created, it immediately
        starts training on the data found in the specified Amazon S3 bucket. Training
        can take 30 minutes or longer. The `describe_document_classifier` function
        can be used to get training status and returns a status of TRAINED when the
        classifier is ready to use.

        :param name: The name of the classifier.
        :param language_code: The language the classifier can operate on.
        :param training_bucket: The Amazon S3 bucket that contains the training data.
        :param training_key: The prefix used to find training data in the training
                             bucket. If multiple objects have the same prefix, all
                             of them are used.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     training bucket.
        :return: The ARN of the newly created classifier.
        """
        try:
            response = self.comprehend_client.create_document_classifier(
                DocumentClassifierName=name,
                LanguageCode=language_code,
                InputDataConfig={"S3Uri": f"s3://{training_bucket}/{training_key}"},
                DataAccessRoleArn=data_access_role_arn,
                Mode=mode.value,
            )
            self.classifier_arn = response["DocumentClassifierArn"]
            logger.info("Started classifier creation. Arn is: %s.", self.classifier_arn)
        except ClientError:
            logger.exception("Couldn't create classifier %s.", name)
            raise
        else:
            return self.classifier_arn
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [CreateDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/CreateDocumentClassifier)。

### `DeleteDocumentClassifier`
<a name="comprehend_DeleteDocumentClassifier_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DeleteDocumentClassifier`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def delete(self):
        """
        Deletes the classifier.
        """
        try:
            self.comprehend_client.delete_document_classifier(
                DocumentClassifierArn=self.classifier_arn
            )
            logger.info("Deleted classifier %s.", self.classifier_arn)
            self.classifier_arn = None
        except ClientError:
            logger.exception("Couldn't deleted classifier %s.", self.classifier_arn)
            raise
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DeleteDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DeleteDocumentClassifier)。

### `DescribeDocumentClassificationJob`
<a name="comprehend_DescribeDocumentClassificationJob_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DescribeDocumentClassificationJob`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def describe_job(self, job_id):
        """
        Gets metadata about a classification job.

        :param job_id: The ID of the job to look up.
        :return: Metadata about the job.
        """
        try:
            response = self.comprehend_client.describe_document_classification_job(
                JobId=job_id
            )
            job = response["DocumentClassificationJobProperties"]
            logger.info("Got classification job %s.", job["JobName"])
        except ClientError:
            logger.exception("Couldn't get classification job %s.", job_id)
            raise
        else:
            return job
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DescribeDocumentClassificationJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeDocumentClassificationJob)。

### `DescribeDocumentClassifier`
<a name="comprehend_DescribeDocumentClassifier_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DescribeDocumentClassifier`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def describe(self, classifier_arn=None):
        """
        Gets metadata about a custom classifier, including its current status.

        :param classifier_arn: The ARN of the classifier to look up.
        :return: Metadata about the classifier.
        """
        if classifier_arn is not None:
            self.classifier_arn = classifier_arn
        try:
            response = self.comprehend_client.describe_document_classifier(
                DocumentClassifierArn=self.classifier_arn
            )
            classifier = response["DocumentClassifierProperties"]
            logger.info("Got classifier %s.", self.classifier_arn)
        except ClientError:
            logger.exception("Couldn't get classifier %s.", self.classifier_arn)
            raise
        else:
            return classifier
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DescribeDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeDocumentClassifier)。

### `DescribeTopicsDetectionJob`
<a name="comprehend_DescribeTopicsDetectionJob_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DescribeTopicsDetectionJob`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendTopicModeler:
    """Encapsulates a Comprehend topic modeler."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def describe_job(self, job_id):
        """
        Gets metadata about a topic modeling job.

        :param job_id: The ID of the job to look up.
        :return: Metadata about the job.
        """
        try:
            response = self.comprehend_client.describe_topics_detection_job(
                JobId=job_id
            )
            job = response["TopicsDetectionJobProperties"]
            logger.info("Got topic detection job %s.", job_id)
        except ClientError:
            logger.exception("Couldn't get topic detection job %s.", job_id)
            raise
        else:
            return job
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DescribeTopicsDetectionJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeTopicsDetectionJob)。

### `DetectDominantLanguage`
<a name="comprehend_DetectDominantLanguage_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectDominantLanguage`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_languages(self, text):
        """
        Detects languages used in a document.

        :param text: The document to inspect.
        :return: The list of languages along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_dominant_language(Text=text)
            languages = response["Languages"]
            logger.info("Detected %s languages.", len(languages))
        except ClientError:
            logger.exception("Couldn't detect languages.")
            raise
        else:
            return languages
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectDominantLanguage](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectDominantLanguage)。

### `DetectEntities`
<a name="comprehend_DetectEntities_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectEntities`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_entities(self, text, language_code):
        """
        Detects entities in a document. Entities can be things like people and places
        or other common terms.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of entities along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_entities(
                Text=text, LanguageCode=language_code
            )
            entities = response["Entities"]
            logger.info("Detected %s entities.", len(entities))
        except ClientError:
            logger.exception("Couldn't detect entities.")
            raise
        else:
            return entities
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectEntities](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectEntities)。

### `DetectKeyPhrases`
<a name="comprehend_DetectKeyPhrases_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectKeyPhrases`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_key_phrases(self, text, language_code):
        """
        Detects key phrases in a document. A key phrase is typically a noun and its
        modifiers.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of key phrases along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_key_phrases(
                Text=text, LanguageCode=language_code
            )
            phrases = response["KeyPhrases"]
            logger.info("Detected %s phrases.", len(phrases))
        except ClientError:
            logger.exception("Couldn't detect phrases.")
            raise
        else:
            return phrases
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectKeyPhrases](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectKeyPhrases)。

### `DetectPiiEntities`
<a name="comprehend_DetectPiiEntities_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectPiiEntities`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_pii(self, text, language_code):
        """
        Detects personally identifiable information (PII) in a document. PII can be
        things like names, account numbers, or addresses.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of PII entities along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_pii_entities(
                Text=text, LanguageCode=language_code
            )
            entities = response["Entities"]
            logger.info("Detected %s PII entities.", len(entities))
        except ClientError:
            logger.exception("Couldn't detect PII entities.")
            raise
        else:
            return entities
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectPiiEntities](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectPiiEntities)。

### `DetectSentiment`
<a name="comprehend_DetectSentiment_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectSentiment`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_sentiment(self, text, language_code):
        """
        Detects the overall sentiment expressed in a document. Sentiment can
        be positive, negative, neutral, or a mixture.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The sentiments along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_sentiment(
                Text=text, LanguageCode=language_code
            )
            logger.info("Detected primary sentiment %s.", response["Sentiment"])
        except ClientError:
            logger.exception("Couldn't detect sentiment.")
            raise
        else:
            return response
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectSentiment](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectSentiment)。

### `DetectSyntax`
<a name="comprehend_DetectSyntax_python_3_topic"></a>

以下程式碼範例顯示如何使用 `DetectSyntax`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_syntax(self, text, language_code):
        """
        Detects syntactical elements of a document. Syntax tokens are portions of
        text along with their use as parts of speech, such as nouns, verbs, and
        interjections.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of syntax tokens along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_syntax(
                Text=text, LanguageCode=language_code
            )
            tokens = response["SyntaxTokens"]
            logger.info("Detected %s syntax tokens.", len(tokens))
        except ClientError:
            logger.exception("Couldn't detect syntax.")
            raise
        else:
            return tokens
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [DetectSyntax](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectSyntax)。

### `ListDocumentClassificationJobs`
<a name="comprehend_ListDocumentClassificationJobs_python_3_topic"></a>

以下程式碼範例顯示如何使用 `ListDocumentClassificationJobs`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def list_jobs(self):
        """
        Lists the classification jobs for the current account.

        :return: The list of jobs.
        """
        try:
            response = self.comprehend_client.list_document_classification_jobs()
            jobs = response["DocumentClassificationJobPropertiesList"]
            logger.info("Got %s document classification jobs.", len(jobs))
        except ClientError:
            logger.exception(
                "Couldn't get document classification jobs.",
            )
            raise
        else:
            return jobs
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [ListDocumentClassificationJobs](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListDocumentClassificationJobs)。

### `ListDocumentClassifiers`
<a name="comprehend_ListDocumentClassifiers_python_3_topic"></a>

以下程式碼範例顯示如何使用 `ListDocumentClassifiers`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def list(self):
        """
        Lists custom classifiers for the current account.

        :return: The list of classifiers.
        """
        try:
            response = self.comprehend_client.list_document_classifiers()
            classifiers = response["DocumentClassifierPropertiesList"]
            logger.info("Got %s classifiers.", len(classifiers))
        except ClientError:
            logger.exception(
                "Couldn't get classifiers.",
            )
            raise
        else:
            return classifiers
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [ListDocumentClassifiers](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListDocumentClassifiers)。

### `ListTopicsDetectionJobs`
<a name="comprehend_ListTopicsDetectionJobs_python_3_topic"></a>

以下程式碼範例顯示如何使用 `ListTopicsDetectionJobs`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendTopicModeler:
    """Encapsulates a Comprehend topic modeler."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def list_jobs(self):
        """
        Lists topic modeling jobs for the current account.

        :return: The list of jobs.
        """
        try:
            response = self.comprehend_client.list_topics_detection_jobs()
            jobs = response["TopicsDetectionJobPropertiesList"]
            logger.info("Got %s topic detection jobs.", len(jobs))
        except ClientError:
            logger.exception("Couldn't get topic detection jobs.")
            raise
        else:
            return jobs
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [ListTopicsDetectionJobs](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListTopicsDetectionJobs)。

### `StartDocumentClassificationJob`
<a name="comprehend_StartDocumentClassificationJob_python_3_topic"></a>

以下程式碼範例顯示如何使用 `StartDocumentClassificationJob`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def start_job(
        self,
        job_name,
        input_bucket,
        input_key,
        input_format,
        output_bucket,
        output_key,
        data_access_role_arn,
    ):
        """
        Starts a classification job. The classifier must be trained or the job
        will fail. Input is read from the specified Amazon S3 input bucket and
        written to the specified output bucket. Output data is stored in a tar
        archive compressed in gzip format. The job runs asynchronously, so you can
        call `describe_document_classification_job` to get job status until it
        returns a status of SUCCEEDED.

        :param job_name: The name of the job.
        :param input_bucket: The Amazon S3 bucket that contains input data.
        :param input_key: The prefix used to find input data in the input
                          bucket. If multiple objects have the same prefix, all
                          of them are used.
        :param input_format: The format of the input data, either one document per
                             file or one document per line.
        :param output_bucket: The Amazon S3 bucket where output data is written.
        :param output_key: The prefix prepended to the output data.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     input bucket and write to the output bucket.
        :return: Information about the job, including the job ID.
        """
        try:
            response = self.comprehend_client.start_document_classification_job(
                DocumentClassifierArn=self.classifier_arn,
                JobName=job_name,
                InputDataConfig={
                    "S3Uri": f"s3://{input_bucket}/{input_key}",
                    "InputFormat": input_format.value,
                },
                OutputDataConfig={"S3Uri": f"s3://{output_bucket}/{output_key}"},
                DataAccessRoleArn=data_access_role_arn,
            )
            logger.info(
                "Document classification job %s is %s.", job_name, response["JobStatus"]
            )
        except ClientError:
            logger.exception("Couldn't start classification job %s.", job_name)
            raise
        else:
            return response
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [StartDocumentClassificationJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/StartDocumentClassificationJob)。

### `StartTopicsDetectionJob`
<a name="comprehend_StartTopicsDetectionJob_python_3_topic"></a>

以下程式碼範例顯示如何使用 `StartTopicsDetectionJob`。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。

```
class ComprehendTopicModeler:
    """Encapsulates a Comprehend topic modeler."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def start_job(
        self,
        job_name,
        input_bucket,
        input_key,
        input_format,
        output_bucket,
        output_key,
        data_access_role_arn,
    ):
        """
        Starts a topic modeling job. Input is read from the specified Amazon S3
        input bucket and written to the specified output bucket. Output data is stored
        in a tar archive compressed in gzip format. The job runs asynchronously, so you
        can call `describe_topics_detection_job` to get job status until it
        returns a status of SUCCEEDED.

        :param job_name: The name of the job.
        :param input_bucket: An Amazon S3 bucket that contains job input.
        :param input_key: The prefix used to find input data in the input
                             bucket. If multiple objects have the same prefix, all
                             of them are used.
        :param input_format: The format of the input data, either one document per
                             file or one document per line.
        :param output_bucket: The Amazon S3 bucket where output data is written.
        :param output_key: The prefix prepended to the output data.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     input bucket and write to the output bucket.
        :return: Information about the job, including the job ID.
        """
        try:
            response = self.comprehend_client.start_topics_detection_job(
                JobName=job_name,
                DataAccessRoleArn=data_access_role_arn,
                InputDataConfig={
                    "S3Uri": f"s3://{input_bucket}/{input_key}",
                    "InputFormat": input_format.value,
                },
                OutputDataConfig={"S3Uri": f"s3://{output_bucket}/{output_key}"},
            )
            logger.info("Started topic modeling job %s.", response["JobId"])
        except ClientError:
            logger.exception("Couldn't start topic modeling job.")
            raise
        else:
            return response
```
+  如需 API 詳細資訊，請參閱《AWS SDK for Python (Boto3) API 參考》**中的 [StartTopicsDetectionJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/StartTopicsDetectionJob)。

## 案例
<a name="scenarios"></a>

### 偵測文件元素
<a name="comprehend_Usage_DetectApis_python_3_topic"></a>

以下程式碼範例顯示做法：
+ 偵測文件中的語言、實體和關鍵片語。
+ 偵測文件中的個人身分識別資訊 (PII)。
+ 偵測文件的情緒。
+ 偵測文件中的語法元素。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。
建立包裝 Amazon Comprehend 動作的類別。  

```
import logging
from pprint import pprint
import boto3
from botocore.exceptions import ClientError

logger = logging.getLogger(__name__)

class ComprehendDetect:
    """Encapsulates Comprehend detection functions."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def detect_languages(self, text):
        """
        Detects languages used in a document.

        :param text: The document to inspect.
        :return: The list of languages along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_dominant_language(Text=text)
            languages = response["Languages"]
            logger.info("Detected %s languages.", len(languages))
        except ClientError:
            logger.exception("Couldn't detect languages.")
            raise
        else:
            return languages


    def detect_entities(self, text, language_code):
        """
        Detects entities in a document. Entities can be things like people and places
        or other common terms.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of entities along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_entities(
                Text=text, LanguageCode=language_code
            )
            entities = response["Entities"]
            logger.info("Detected %s entities.", len(entities))
        except ClientError:
            logger.exception("Couldn't detect entities.")
            raise
        else:
            return entities


    def detect_key_phrases(self, text, language_code):
        """
        Detects key phrases in a document. A key phrase is typically a noun and its
        modifiers.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of key phrases along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_key_phrases(
                Text=text, LanguageCode=language_code
            )
            phrases = response["KeyPhrases"]
            logger.info("Detected %s phrases.", len(phrases))
        except ClientError:
            logger.exception("Couldn't detect phrases.")
            raise
        else:
            return phrases


    def detect_pii(self, text, language_code):
        """
        Detects personally identifiable information (PII) in a document. PII can be
        things like names, account numbers, or addresses.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of PII entities along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_pii_entities(
                Text=text, LanguageCode=language_code
            )
            entities = response["Entities"]
            logger.info("Detected %s PII entities.", len(entities))
        except ClientError:
            logger.exception("Couldn't detect PII entities.")
            raise
        else:
            return entities


    def detect_sentiment(self, text, language_code):
        """
        Detects the overall sentiment expressed in a document. Sentiment can
        be positive, negative, neutral, or a mixture.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The sentiments along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_sentiment(
                Text=text, LanguageCode=language_code
            )
            logger.info("Detected primary sentiment %s.", response["Sentiment"])
        except ClientError:
            logger.exception("Couldn't detect sentiment.")
            raise
        else:
            return response


    def detect_syntax(self, text, language_code):
        """
        Detects syntactical elements of a document. Syntax tokens are portions of
        text along with their use as parts of speech, such as nouns, verbs, and
        interjections.

        :param text: The document to inspect.
        :param language_code: The language of the document.
        :return: The list of syntax tokens along with their confidence scores.
        """
        try:
            response = self.comprehend_client.detect_syntax(
                Text=text, LanguageCode=language_code
            )
            tokens = response["SyntaxTokens"]
            logger.info("Detected %s syntax tokens.", len(tokens))
        except ClientError:
            logger.exception("Couldn't detect syntax.")
            raise
        else:
            return tokens
```
呼叫在包裝函式類別上的函數，以偵測文件中的實體、片語等。  

```
def usage_demo():
    print("-" * 88)
    print("Welcome to the Amazon Comprehend detection demo!")
    print("-" * 88)

    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    comp_detect = ComprehendDetect(boto3.client("comprehend"))
    with open("detect_sample.txt") as sample_file:
        sample_text = sample_file.read()

    demo_size = 3

    print("Sample text used for this demo:")
    print("-" * 88)
    print(sample_text)
    print("-" * 88)

    print("Detecting languages.")
    languages = comp_detect.detect_languages(sample_text)
    pprint(languages)
    lang_code = languages[0]["LanguageCode"]

    print("Detecting entities.")
    entities = comp_detect.detect_entities(sample_text, lang_code)
    print(f"The first {demo_size} are:")
    pprint(entities[:demo_size])

    print("Detecting key phrases.")
    phrases = comp_detect.detect_key_phrases(sample_text, lang_code)
    print(f"The first {demo_size} are:")
    pprint(phrases[:demo_size])

    print("Detecting personally identifiable information (PII).")
    pii_entities = comp_detect.detect_pii(sample_text, lang_code)
    print(f"The first {demo_size} are:")
    pprint(pii_entities[:demo_size])

    print("Detecting sentiment.")
    sentiment = comp_detect.detect_sentiment(sample_text, lang_code)
    print(f"Sentiment: {sentiment['Sentiment']}")
    print("SentimentScore:")
    pprint(sentiment["SentimentScore"])

    print("Detecting syntax elements.")
    syntax_tokens = comp_detect.detect_syntax(sample_text, lang_code)
    print(f"The first {demo_size} are:")
    pprint(syntax_tokens[:demo_size])

    print("Thanks for watching!")
    print("-" * 88)
```
+ 如需 API 詳細資訊，請參閱《適用於 Python (Boto3) 的AWS SDK API 參考》**中的下列主題。
  + [DetectDominantLanguage](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectDominantLanguage)
  + [DetectEntities](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectEntities)
  + [DetectKeyPhrases](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectKeyPhrases)
  + [DetectPiiEntities](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectPiiEntities)
  + [DetectSentiment](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectSentiment)
  + [DetectSyntax](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DetectSyntax)

### 偵測從影像擷取的文字中的實體
<a name="cross_TextractComprehendDetectEntities_python_3_topic"></a>

下列程式碼範例示範如何使用 Amazon Comprehend 偵測 Amazon Textract 從存放在 Amazon S3 中的影像中提取的文字中的實體。

**適用於 Python 的 SDK (Boto3)**  
 顯示如何使用 Jupyter 筆記本 適用於 Python (Boto3) 的 AWS SDK 中的 來偵測從影像擷取的文字中的實體。本範例使用 Amazon Textract 從儲存於 Amazon Simple Storage Service (Amazon S3) 和 Amazon Comprehend 中的影像提取文字，以偵測擷取文字中的實體。  
 此範例是 Jupyter 的筆記型電腦，必須在可以託管的筆記型電腦的環境中運行。如需使用 Amazon SageMaker AI 執行範例的指示，請參閱 [TextractAndComprehendNotebook.ipynb](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/textract_comprehend_notebook/TextractAndComprehendNotebook.ipynb) 中的說明。  
 如需完整的原始碼和如何設定及執行的指示，請參閱 [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/textract_comprehend_notebook#readme) 上的完整範例。  

**此範例中使用的服務**
+ Amazon Comprehend
+ Amazon S3
+ Amazon Textract

### 針對範例資料執行主題建模任務
<a name="comprehend_Usage_TopicModeler_python_3_topic"></a>

以下程式碼範例顯示做法：
+ 對範例資料執行 Amazon Comprehend 主題建模任務。
+ 取得任務相關資訊。
+ 從 Amazon S3 擷取任務輸出資料。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。
建立包裝函式類別以呼叫 Amazon Comprehend 主題建模動作。  

```
class ComprehendTopicModeler:
    """Encapsulates a Comprehend topic modeler."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client


    def start_job(
        self,
        job_name,
        input_bucket,
        input_key,
        input_format,
        output_bucket,
        output_key,
        data_access_role_arn,
    ):
        """
        Starts a topic modeling job. Input is read from the specified Amazon S3
        input bucket and written to the specified output bucket. Output data is stored
        in a tar archive compressed in gzip format. The job runs asynchronously, so you
        can call `describe_topics_detection_job` to get job status until it
        returns a status of SUCCEEDED.

        :param job_name: The name of the job.
        :param input_bucket: An Amazon S3 bucket that contains job input.
        :param input_key: The prefix used to find input data in the input
                             bucket. If multiple objects have the same prefix, all
                             of them are used.
        :param input_format: The format of the input data, either one document per
                             file or one document per line.
        :param output_bucket: The Amazon S3 bucket where output data is written.
        :param output_key: The prefix prepended to the output data.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     input bucket and write to the output bucket.
        :return: Information about the job, including the job ID.
        """
        try:
            response = self.comprehend_client.start_topics_detection_job(
                JobName=job_name,
                DataAccessRoleArn=data_access_role_arn,
                InputDataConfig={
                    "S3Uri": f"s3://{input_bucket}/{input_key}",
                    "InputFormat": input_format.value,
                },
                OutputDataConfig={"S3Uri": f"s3://{output_bucket}/{output_key}"},
            )
            logger.info("Started topic modeling job %s.", response["JobId"])
        except ClientError:
            logger.exception("Couldn't start topic modeling job.")
            raise
        else:
            return response


    def describe_job(self, job_id):
        """
        Gets metadata about a topic modeling job.

        :param job_id: The ID of the job to look up.
        :return: Metadata about the job.
        """
        try:
            response = self.comprehend_client.describe_topics_detection_job(
                JobId=job_id
            )
            job = response["TopicsDetectionJobProperties"]
            logger.info("Got topic detection job %s.", job_id)
        except ClientError:
            logger.exception("Couldn't get topic detection job %s.", job_id)
            raise
        else:
            return job


    def list_jobs(self):
        """
        Lists topic modeling jobs for the current account.

        :return: The list of jobs.
        """
        try:
            response = self.comprehend_client.list_topics_detection_jobs()
            jobs = response["TopicsDetectionJobPropertiesList"]
            logger.info("Got %s topic detection jobs.", len(jobs))
        except ClientError:
            logger.exception("Couldn't get topic detection jobs.")
            raise
        else:
            return jobs
```
使用包裝函式類別來執行主題建模任務，並取得任務資料。  

```
def usage_demo():
    print("-" * 88)
    print("Welcome to the Amazon Comprehend topic modeling demo!")
    print("-" * 88)

    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    input_prefix = "input/"
    output_prefix = "output/"
    demo_resources = ComprehendDemoResources(
        boto3.resource("s3"), boto3.resource("iam")
    )
    topic_modeler = ComprehendTopicModeler(boto3.client("comprehend"))

    print("Setting up storage and security resources needed for the demo.")
    demo_resources.setup("comprehend-topic-modeler-demo")
    print("Copying sample data from public bucket into input bucket.")
    demo_resources.bucket.copy(
        {"Bucket": "public-sample-us-west-2", "Key": "TopicModeling/Sample.txt"},
        f"{input_prefix}sample.txt",
    )

    print("Starting topic modeling job on sample data.")
    job_info = topic_modeler.start_job(
        "demo-topic-modeling-job",
        demo_resources.bucket.name,
        input_prefix,
        JobInputFormat.per_line,
        demo_resources.bucket.name,
        output_prefix,
        demo_resources.data_access_role.arn,
    )

    print(
        f"Waiting for job {job_info['JobId']} to complete. This typically takes "
        f"20 - 30 minutes."
    )
    job_waiter = JobCompleteWaiter(topic_modeler.comprehend_client)
    job_waiter.wait(job_info["JobId"])

    job = topic_modeler.describe_job(job_info["JobId"])
    print(f"Job {job['JobId']} complete:")
    pprint(job)

    print(
        f"Getting job output data from the output Amazon S3 bucket: "
        f"{job['OutputDataConfig']['S3Uri']}."
    )
    job_output = demo_resources.extract_job_output(job)
    lines = 10
    print(f"First {lines} lines of document topics output:")
    pprint(job_output["doc-topics.csv"]["data"][:lines])
    print(f"First {lines} lines of terms output:")
    pprint(job_output["topic-terms.csv"]["data"][:lines])

    print("Cleaning up resources created for the demo.")
    demo_resources.cleanup()

    print("Thanks for watching!")
    print("-" * 88)
```
+ 如需 API 詳細資訊，請參閱《適用於 Python (Boto3) 的AWS SDK API 參考》**中的下列主題。
  + [DescribeTopicsDetectionJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeTopicsDetectionJob)
  + [ListTopicsDetectionJobs](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListTopicsDetectionJobs)
  + [StartTopicsDetectionJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/StartTopicsDetectionJob)

### 訓練自訂分類器並分類文件
<a name="comprehend_Usage_ComprehendClassifier_python_3_topic"></a>

以下程式碼範例顯示做法：
+ 建立 Amazon Comprehend 多標籤分類器。
+ 根據範例資料訓練分類器。
+ 在第二組資料上執行分類任務。
+ 從 Amazon S3 擷取任務輸出資料。

**適用於 Python 的 SDK (Boto3)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/comprehend#code-examples)中設定和執行。
建立包裝函式類別以呼叫 Amazon Comprehend 文件分類器動作。  

```
class ComprehendClassifier:
    """Encapsulates an Amazon Comprehend custom classifier."""

    def __init__(self, comprehend_client):
        """
        :param comprehend_client: A Boto3 Comprehend client.
        """
        self.comprehend_client = comprehend_client
        self.classifier_arn = None


    def create(
        self,
        name,
        language_code,
        training_bucket,
        training_key,
        data_access_role_arn,
        mode,
    ):
        """
        Creates a custom classifier. After the classifier is created, it immediately
        starts training on the data found in the specified Amazon S3 bucket. Training
        can take 30 minutes or longer. The `describe_document_classifier` function
        can be used to get training status and returns a status of TRAINED when the
        classifier is ready to use.

        :param name: The name of the classifier.
        :param language_code: The language the classifier can operate on.
        :param training_bucket: The Amazon S3 bucket that contains the training data.
        :param training_key: The prefix used to find training data in the training
                             bucket. If multiple objects have the same prefix, all
                             of them are used.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     training bucket.
        :return: The ARN of the newly created classifier.
        """
        try:
            response = self.comprehend_client.create_document_classifier(
                DocumentClassifierName=name,
                LanguageCode=language_code,
                InputDataConfig={"S3Uri": f"s3://{training_bucket}/{training_key}"},
                DataAccessRoleArn=data_access_role_arn,
                Mode=mode.value,
            )
            self.classifier_arn = response["DocumentClassifierArn"]
            logger.info("Started classifier creation. Arn is: %s.", self.classifier_arn)
        except ClientError:
            logger.exception("Couldn't create classifier %s.", name)
            raise
        else:
            return self.classifier_arn


    def describe(self, classifier_arn=None):
        """
        Gets metadata about a custom classifier, including its current status.

        :param classifier_arn: The ARN of the classifier to look up.
        :return: Metadata about the classifier.
        """
        if classifier_arn is not None:
            self.classifier_arn = classifier_arn
        try:
            response = self.comprehend_client.describe_document_classifier(
                DocumentClassifierArn=self.classifier_arn
            )
            classifier = response["DocumentClassifierProperties"]
            logger.info("Got classifier %s.", self.classifier_arn)
        except ClientError:
            logger.exception("Couldn't get classifier %s.", self.classifier_arn)
            raise
        else:
            return classifier


    def list(self):
        """
        Lists custom classifiers for the current account.

        :return: The list of classifiers.
        """
        try:
            response = self.comprehend_client.list_document_classifiers()
            classifiers = response["DocumentClassifierPropertiesList"]
            logger.info("Got %s classifiers.", len(classifiers))
        except ClientError:
            logger.exception(
                "Couldn't get classifiers.",
            )
            raise
        else:
            return classifiers


    def delete(self):
        """
        Deletes the classifier.
        """
        try:
            self.comprehend_client.delete_document_classifier(
                DocumentClassifierArn=self.classifier_arn
            )
            logger.info("Deleted classifier %s.", self.classifier_arn)
            self.classifier_arn = None
        except ClientError:
            logger.exception("Couldn't deleted classifier %s.", self.classifier_arn)
            raise


    def start_job(
        self,
        job_name,
        input_bucket,
        input_key,
        input_format,
        output_bucket,
        output_key,
        data_access_role_arn,
    ):
        """
        Starts a classification job. The classifier must be trained or the job
        will fail. Input is read from the specified Amazon S3 input bucket and
        written to the specified output bucket. Output data is stored in a tar
        archive compressed in gzip format. The job runs asynchronously, so you can
        call `describe_document_classification_job` to get job status until it
        returns a status of SUCCEEDED.

        :param job_name: The name of the job.
        :param input_bucket: The Amazon S3 bucket that contains input data.
        :param input_key: The prefix used to find input data in the input
                          bucket. If multiple objects have the same prefix, all
                          of them are used.
        :param input_format: The format of the input data, either one document per
                             file or one document per line.
        :param output_bucket: The Amazon S3 bucket where output data is written.
        :param output_key: The prefix prepended to the output data.
        :param data_access_role_arn: The Amazon Resource Name (ARN) of a role that
                                     grants Comprehend permission to read from the
                                     input bucket and write to the output bucket.
        :return: Information about the job, including the job ID.
        """
        try:
            response = self.comprehend_client.start_document_classification_job(
                DocumentClassifierArn=self.classifier_arn,
                JobName=job_name,
                InputDataConfig={
                    "S3Uri": f"s3://{input_bucket}/{input_key}",
                    "InputFormat": input_format.value,
                },
                OutputDataConfig={"S3Uri": f"s3://{output_bucket}/{output_key}"},
                DataAccessRoleArn=data_access_role_arn,
            )
            logger.info(
                "Document classification job %s is %s.", job_name, response["JobStatus"]
            )
        except ClientError:
            logger.exception("Couldn't start classification job %s.", job_name)
            raise
        else:
            return response


    def describe_job(self, job_id):
        """
        Gets metadata about a classification job.

        :param job_id: The ID of the job to look up.
        :return: Metadata about the job.
        """
        try:
            response = self.comprehend_client.describe_document_classification_job(
                JobId=job_id
            )
            job = response["DocumentClassificationJobProperties"]
            logger.info("Got classification job %s.", job["JobName"])
        except ClientError:
            logger.exception("Couldn't get classification job %s.", job_id)
            raise
        else:
            return job


    def list_jobs(self):
        """
        Lists the classification jobs for the current account.

        :return: The list of jobs.
        """
        try:
            response = self.comprehend_client.list_document_classification_jobs()
            jobs = response["DocumentClassificationJobPropertiesList"]
            logger.info("Got %s document classification jobs.", len(jobs))
        except ClientError:
            logger.exception(
                "Couldn't get document classification jobs.",
            )
            raise
        else:
            return jobs
```
建立類別以協助執行案例。  

```
class ClassifierDemo:
    """
    Encapsulates functions used to run the demonstration.
    """

    def __init__(self, demo_resources):
        """
        :param demo_resources: A ComprehendDemoResources class that manages resources
                               for the demonstration.
        """
        self.demo_resources = demo_resources
        self.training_prefix = "training/"
        self.input_prefix = "input/"
        self.input_format = JobInputFormat.per_line
        self.output_prefix = "output/"

    def setup(self):
        """Creates AWS resources used by the demo."""
        self.demo_resources.setup("comprehend-classifier-demo")

    def cleanup(self):
        """Deletes AWS resources used by the demo."""
        self.demo_resources.cleanup()

    @staticmethod
    def _sanitize_text(text):
        """Removes characters that cause errors for the document parser."""
        return text.replace("\r", " ").replace("\n", " ").replace(",", ";")

    @staticmethod
    def _get_issues(query, issue_count):
        """
        Gets issues from GitHub using the specified query parameters.

        :param query: The query string used to request issues from the GitHub API.
        :param issue_count: The number of issues to retrieve.
        :return: The list of issues retrieved from GitHub.
        """
        issues = []
        logger.info("Requesting issues from %s?%s.", GITHUB_SEARCH_URL, query)
        response = requests.get(f"{GITHUB_SEARCH_URL}?{query}&per_page={issue_count}")
        if response.status_code == 200:
            issue_page = response.json()["items"]
            logger.info("Got %s issues.", len(issue_page))
            issues = [
                {
                    "title": ClassifierDemo._sanitize_text(issue["title"]),
                    "body": ClassifierDemo._sanitize_text(issue["body"]),
                    "labels": {label["name"] for label in issue["labels"]},
                }
                for issue in issue_page
            ]
        else:
            logger.error(
                "GitHub returned error code %s with message %s.",
                response.status_code,
                response.json(),
            )
        logger.info("Found %s issues.", len(issues))
        return issues

    def get_training_issues(self, training_labels):
        """
        Gets issues used for training the custom classifier. Training issues are
        closed issues from the Boto3 repo that have known labels. Comprehend
        requires a minimum of ten training issues per label.

        :param training_labels: The issue labels to use for training.
        :return: The set of issues used for training.
        """
        issues = []
        per_label_count = 15
        for label in training_labels:
            issues += self._get_issues(
                f"q=type:issue+repo:boto/boto3+state:closed+label:{label}",
                per_label_count,
            )
            for issue in issues:
                issue["labels"] = issue["labels"].intersection(training_labels)
        return issues

    def get_input_issues(self, training_labels):
        """
        Gets input issues from GitHub. For demonstration purposes, input issues
        are open issues from the Boto3 repo with known labels, though in practice
        any issue could be submitted to the classifier for labeling.

        :param training_labels: The set of labels to query for.
        :return: The set of issues used for input.
        """
        issues = []
        per_label_count = 5
        for label in training_labels:
            issues += self._get_issues(
                f"q=type:issue+repo:boto/boto3+state:open+label:{label}",
                per_label_count,
            )
        return issues

    def upload_issue_data(self, issues, training=False):
        """
        Uploads issue data to an Amazon S3 bucket, either for training or for input.
        The data is first put into the format expected by Comprehend. For training,
        the set of pipe-delimited labels is prepended to each document. For
        input, labels are not sent.

        :param issues: The set of issues to upload to Amazon S3.
        :param training: Indicates whether the issue data is used for training or
                         input.
        """
        try:
            obj_key = (
                self.training_prefix if training else self.input_prefix
            ) + "issues.txt"
            if training:
                issue_strings = [
                    f"{'|'.join(issue['labels'])},{issue['title']} {issue['body']}"
                    for issue in issues
                ]
            else:
                issue_strings = [
                    f"{issue['title']} {issue['body']}" for issue in issues
                ]
            issue_bytes = BytesIO("\n".join(issue_strings).encode("utf-8"))
            self.demo_resources.bucket.upload_fileobj(issue_bytes, obj_key)
            logger.info(
                "Uploaded data as %s to bucket %s.",
                obj_key,
                self.demo_resources.bucket.name,
            )
        except ClientError:
            logger.exception(
                "Couldn't upload data to bucket %s.", self.demo_resources.bucket.name
            )
            raise

    def extract_job_output(self, job):
        """Extracts job output from Amazon S3."""
        return self.demo_resources.extract_job_output(job)

    @staticmethod
    def reconcile_job_output(input_issues, output_dict):
        """
        Reconciles job output with the list of input issues. Because the input issues
        have known labels, these can be compared with the labels added by the
        classifier to judge the accuracy of the output.

        :param input_issues: The list of issues used as input.
        :param output_dict: The dictionary of data that is output by the classifier.
        :return: The list of reconciled input and output data.
        """
        reconciled = []
        for archive in output_dict.values():
            for line in archive["data"]:
                in_line = int(line["Line"])
                in_labels = input_issues[in_line]["labels"]
                out_labels = {
                    label["Name"]
                    for label in line["Labels"]
                    if float(label["Score"]) > 0.3
                }
                reconciled.append(
                    f"{line['File']}, line {in_line} has labels {in_labels}.\n"
                    f"\tClassifier assigned {out_labels}."
                )
        logger.info("Reconciled input and output labels.")
        return reconciled
```
使用已知標籤在一組 GitHub 問題上訓練分類器，然後將第二組 GitHub 問題傳送到分類器，以便針對問題進行標記。  

```
def usage_demo():
    print("-" * 88)
    print("Welcome to the Amazon Comprehend custom document classifier demo!")
    print("-" * 88)

    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    comp_demo = ClassifierDemo(
        ComprehendDemoResources(boto3.resource("s3"), boto3.resource("iam"))
    )
    comp_classifier = ComprehendClassifier(boto3.client("comprehend"))
    classifier_trained_waiter = ClassifierTrainedWaiter(
        comp_classifier.comprehend_client
    )
    training_labels = {"bug", "feature-request", "dynamodb", "s3"}

    print("Setting up storage and security resources needed for the demo.")
    comp_demo.setup()

    print("Getting training data from GitHub and uploading it to Amazon S3.")
    training_issues = comp_demo.get_training_issues(training_labels)
    comp_demo.upload_issue_data(training_issues, True)

    classifier_name = "doc-example-classifier"
    print(f"Creating document classifier {classifier_name}.")
    comp_classifier.create(
        classifier_name,
        "en",
        comp_demo.demo_resources.bucket.name,
        comp_demo.training_prefix,
        comp_demo.demo_resources.data_access_role.arn,
        ClassifierMode.multi_label,
    )
    print(
        f"Waiting until {classifier_name} is trained. This typically takes "
        f"30–40 minutes."
    )
    classifier_trained_waiter.wait(comp_classifier.classifier_arn)

    print(f"Classifier {classifier_name} is trained:")
    pprint(comp_classifier.describe())

    print("Getting input data from GitHub and uploading it to Amazon S3.")
    input_issues = comp_demo.get_input_issues(training_labels)
    comp_demo.upload_issue_data(input_issues)

    print("Starting classification job on input data.")
    job_info = comp_classifier.start_job(
        "issue_classification_job",
        comp_demo.demo_resources.bucket.name,
        comp_demo.input_prefix,
        comp_demo.input_format,
        comp_demo.demo_resources.bucket.name,
        comp_demo.output_prefix,
        comp_demo.demo_resources.data_access_role.arn,
    )
    print(f"Waiting for job {job_info['JobId']} to complete.")
    job_waiter = JobCompleteWaiter(comp_classifier.comprehend_client)
    job_waiter.wait(job_info["JobId"])

    job = comp_classifier.describe_job(job_info["JobId"])
    print(f"Job {job['JobId']} complete:")
    pprint(job)

    print(
        f"Getting job output data from Amazon S3: "
        f"{job['OutputDataConfig']['S3Uri']}."
    )
    job_output = comp_demo.extract_job_output(job)
    print("Job output:")
    pprint(job_output)

    print("Reconciling job output with labels from GitHub:")
    reconciled_output = comp_demo.reconcile_job_output(input_issues, job_output)
    print(*reconciled_output, sep="\n")

    answer = input(f"Do you want to delete the classifier {classifier_name} (y/n)? ")
    if answer.lower() == "y":
        print(f"Deleting {classifier_name}.")
        comp_classifier.delete()

    print("Cleaning up resources created for the demo.")
    comp_demo.cleanup()

    print("Thanks for watching!")
    print("-" * 88)
```
+ 如需 API 詳細資訊，請參閱《適用於 Python (Boto3) 的AWS SDK API 參考》**中的下列主題。
  + [CreateDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/CreateDocumentClassifier)
  + [DeleteDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DeleteDocumentClassifier)
  + [DescribeDocumentClassificationJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeDocumentClassificationJob)
  + [DescribeDocumentClassifier](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/DescribeDocumentClassifier)
  + [ListDocumentClassificationJobs](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListDocumentClassificationJobs)
  + [ListDocumentClassifiers](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/ListDocumentClassifiers)
  + [StartDocumentClassificationJob](https://docs.aws.amazon.com/goto/boto3/comprehend-2017-11-27/StartDocumentClassificationJob)