surveydata.dynamodbstorage module

Support for AWS DynamoDB survey data storage.

class surveydata.dynamodbstorage.DynamoDBStorage(aws_region: str, table_name: str, id_field_name: str, partition_key_name: str = '', partition_key_value: str = '', aws_access_key_id: Optional[str] = None, aws_secret_access_key: Optional[str] = None, aws_session_token: Optional[str] = None)

Bases: StorageSystem

AWS DynamoDB survey data storage implementation.

__init__(aws_region: str, table_name: str, id_field_name: str, partition_key_name: str = '', partition_key_value: str = '', aws_access_key_id: Optional[str] = None, aws_secret_access_key: Optional[str] = None, aws_session_token: Optional[str] = None)

Initialize DynamoDB storage for survey data.

Parameters

  • aws_region (str) – AWS region to use

  • table_name (str) – DynamoDB table name (must already exist)

  • id_field_name (str) – Field name for unique submission ID (e.g., “KEY”)

  • partition_key_name (str) – Partition key name for optional fixed partition (e.g., “FormID”)

  • partition_key_value (str) – Partition value for optional fixed partition (e.g., form ID)

  • aws_access_key_id (str) – AWS access key ID; if None, will use local config file and/or environment vars

  • aws_secret_access_key (str) – AWS access key secret; if None, will use local config file and/or environment vars

  • aws_session_token (str) – AWS session token to use, only if using temporary credentials

The DynamoDB table should already exist with the primary key configured in one of two ways:

  1. a fixed partition key with the name passed as partition_key_name, and the sort key with the name passed as id_field_name; or

  2. a partition key with the name passed as id_field_name (and no sort key).

attachments_supported() → bool

Query whether storage system supports attachments.

Returns

True if attachments supported, otherwise False

Return type

bool

get_attachment(attachment_location: str = '', submission_id: str = '', attachment_name: str = '') → BinaryIO

Get submission attachment from storage.

Parameters

  • attachment_location (str) – Attachment location string (as returned when attachment stored)

  • submission_id (str) – Unique submission ID (in lieu of attachment_location)

  • attachment_name (str) – Attachment filename (in lieu of attachment_location)

Returns

Attachment as file-like object (though, note: it doesn’t support seeking)

Return type

BinaryIO

Must pass either attachment_location or both submission_id and attachment_name.

get_metadata(metadata_id: str) → str

Get metadata string from storage.

Parameters

metadata_id (str) – Unique metadata ID (should begin and end with __ and not conflict with any submission ID)

Returns

Metadata string from storage, or empty string if no such metadata exists

Return type

str

get_metadata_binary(metadata_id: str) → bytes

Get metadata bytes from storage.

Parameters

metadata_id (str) – Unique metadata ID (should not conflict with any submission ID)

Returns

Metadata bytes from storage, or empty bytes array if no such metadata exists

Return type

bytes

get_submission(submission_id: str) → dict

Get submission data from storage.

Parameters

submission_id (str) – Unique submission ID

Returns

Submission data (or empty dictionary if submission not found)

Return type

dict

list_attachments(submission_id: str = '') → list

List all attachments currently in storage.

Parameters

submission_id (str) – Optional submission ID, to list only attachments for specific submission

Returns

List of attachments, each as dict with name, submission_id, and location_string

Return type

list

list_submissions() → list

List all submissions currently in storage.

Returns

List of submission IDs

Return type

list

query_attachment(attachment_location: str = '', submission_id: str = '', attachment_name: str = '') → bool

Query whether specific submission attachment exists in storage.

Parameters

  • attachment_location (str) – Attachment location string (as returned when attachment stored)

  • submission_id (str) – Unique submission ID (in lieu of attachment_location)

  • attachment_name (str) – Attachment filename (in lieu of attachment_location)

Returns

True if submission exists in storage; otherwise False

Return type

bool

Must pass either attachment_location or both submission_id and attachment_name.

query_submission(submission_id: str) → bool

Query whether specific submission exists in storage.

Parameters

submission_id (str) – Unique submission ID

Returns

True if submission exists in storage; otherwise False

Return type

bool

store_attachment(submission_id: str, attachment_name: str, attachment_data: BinaryIO) → str

Store submission attachment in storage.

Parameters

  • submission_id (str) – Unique submission ID

  • attachment_name (str) – Attachment filename

  • attachment_data (BinaryIO) – File-type object containing the attachment data

Returns

Location string for stored attachment

Return type

str

store_metadata(metadata_id: str, metadata: str)

Store metadata string in storage.

Parameters

  • metadata_id (str) – Unique metadata ID (should begin and end with __ and not conflict with any submission ID)

  • metadata (str) – Metadata string to store

store_metadata_binary(metadata_id: str, metadata: bytes)

Store metadata bytes in storage.

Parameters

  • metadata_id (str) – Unique metadata ID (should begin and end with __ and not conflict with any submission ID)

  • metadata (bytes) – Metadata bytes to store

store_submission(submission_id: str, submission_data: dict)

Store submission data in storage.

Parameters

  • submission_id (str) – Unique submission ID

  • submission_data (dict) – Submission data to store

submission_primary_key(submission_id: str) → dict

Get submission primary key for specific submission.

Parameters

submission_id (str) – Unique submission ID

Returns

Primary key for submission

Return type

dict