def batch_write_item(RequestItems=None, ReturnConsumedCapacity=None,
    ReturnItemCollectionMetrics=None):
    """
    The BatchWriteItem operation puts or deletes multiple items in one or more tables. A single call to BatchWriteItem can write up to 16 MB of data, which can comprise as many as 25 put or delete requests. Individual items to be written can be as large as 400 KB.
    The individual PutItem and DeleteItem operations specified in BatchWriteItem are atomic; however BatchWriteItem as a whole is not. If any requested operations fail because the table's provisioned throughput is exceeded or an internal processing failure occurs, the failed operations are returned in the UnprocessedItems response parameter. You can investigate and optionally resend the requests. Typically, you would call BatchWriteItem in a loop. Each iteration would check for unprocessed items and submit a new BatchWriteItem request with those unprocessed items until all items have been processed.
    Note that if none of the items can be processed due to insufficient provisioned throughput on all of the tables in the request, then BatchWriteItem will return a ProvisionedThroughputExceededException .
    With BatchWriteItem , you can efficiently write or delete large amounts of data, such as from Amazon Elastic MapReduce (EMR), or copy data from another database into DynamoDB. In order to improve performance with these large-scale operations, BatchWriteItem does not behave in the same way as individual PutItem and DeleteItem calls would. For example, you cannot specify conditions on individual put and delete requests, and BatchWriteItem does not return deleted items in the response.
    If you use a programming language that supports concurrency, you can use threads to write items in parallel. Your application must include the necessary logic to manage the threads. With languages that don't support threading, you must update or delete the specified items one at a time. In both situations, BatchWriteItem performs the specified put and delete operations in parallel, giving you the power of the thread pool approach without having to introduce complexity into your application.
    Parallel processing reduces latency, but each specified put and delete request consumes the same number of write capacity units whether it is processed in parallel or not. Delete operations on nonexistent items consume one write capacity unit.
    If one or more of the following is true, DynamoDB rejects the entire batch write operation:
    See also: AWS API Documentation
    
    Examples
    This example adds three new items to the Music table using a batch of three PutItem requests.
    Expected Output:
    
    :example: response = client.batch_write_item(
        RequestItems={
            'string': [
                {
                    'PutRequest': {
                        'Item': {
                            'string': {
                                'S': 'string',
                                'N': 'string',
                                'B': b'bytes',
                                'SS': [
                                    'string',
                                ],
                                'NS': [
                                    'string',
                                ],
                                'BS': [
                                    b'bytes',
                                ],
                                'M': {
                                    'string': {'... recursive ...'}
                                },
                                'L': [
                                    {'... recursive ...'},
                                ],
                                'NULL': True|False,
                                'BOOL': True|False
                            }
                        }
                    },
                    'DeleteRequest': {
                        'Key': {
                            'string': {
                                'S': 'string',
                                'N': 'string',
                                'B': b'bytes',
                                'SS': [
                                    'string',
                                ],
                                'NS': [
                                    'string',
                                ],
                                'BS': [
                                    b'bytes',
                                ],
                                'M': {
                                    'string': {'... recursive ...'}
                                },
                                'L': [
                                    {'... recursive ...'},
                                ],
                                'NULL': True|False,
                                'BOOL': True|False
                            }
                        }
                    }
                },
            ]
        },
        ReturnConsumedCapacity='INDEXES'|'TOTAL'|'NONE',
        ReturnItemCollectionMetrics='SIZE'|'NONE'
    )
    
    
    :type RequestItems: dict
    :param RequestItems: [REQUIRED]
            A map of one or more table names and, for each table, a list of operations to be performed (DeleteRequest or PutRequest ). Each element in the map consists of the following:
            DeleteRequest - Perform a DeleteItem operation on the specified item. The item to be deleted is identified by a Key subelement:
            Key - A map of primary key attribute values that uniquely identify the ! item. Each entry in this map consists of an attribute name and an attribute value. For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
            PutRequest - Perform a PutItem operation on the specified item. The item to be put is identified by an Item subelement:
            Item - A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with a ValidationException exception. If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
            
            (string) --
            (list) --
            (dict) --Represents an operation to perform - either DeleteItem or PutItem . You can only request one of these operations, not both, in a single WriteRequest . If you do need to perform both of these operations, you will need to provide two separate WriteRequest objects.
            PutRequest (dict) --A request to perform a PutItem operation.
            Item (dict) -- [REQUIRED]A map of attribute name to attribute values, representing the primary key of an item to be processed by PutItem . All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema. If any attributes are present in the item which are part of an index key schema for the table, their types must match the index key schema.
            (string) --
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            S (string) --An attribute of type String. For example:
            'S': 'Hello'
            N (string) --An attribute of type Number. For example:
            'N': '123.45'
            Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
            B (bytes) --An attribute of type Binary. For example:
            'B': 'dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk'
            SS (list) --An attribute of type String Set. For example:
            'SS': ['Giraffe', 'Hippo' ,'Zebra']
            (string) --
            NS (list) --An attribute of type Number Set. For example:
            'NS': ['42.2', '-19', '7.5', '3.14']
            Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
            (string) --
            BS (list) --An attribute of type Binary Set. For example:
            'BS': ['U3Vubnk=', 'UmFpbnk=', 'U25vd3k=']
            (bytes) --
            M (dict) --An attribute of type Map. For example:
            'M': {'Name': {'S': 'Joe'}, 'Age': {'N': '35'}}
            (string) --
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            
            L (list) --An attribute of type List. For example:
            'L': ['Cookies', 'Coffee', 3.14159]
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            NULL (boolean) --An attribute of type Null. For example:
            'NULL': true
            BOOL (boolean) --An attribute of type Boolean. For example:
            'BOOL': true
            
            
            DeleteRequest (dict) --A request to perform a DeleteItem operation.
            Key (dict) -- [REQUIRED]A map of attribute name to attribute values, representing the primary key of the item to delete. All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema.
            (string) --
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            S (string) --An attribute of type String. For example:
            'S': 'Hello'
            N (string) --An attribute of type Number. For example:
            'N': '123.45'
            Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
            B (bytes) --An attribute of type Binary. For example:
            'B': 'dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk'
            SS (list) --An attribute of type String Set. For example:
            'SS': ['Giraffe', 'Hippo' ,'Zebra']
            (string) --
            NS (list) --An attribute of type Number Set. For example:
            'NS': ['42.2', '-19', '7.5', '3.14']
            Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
            (string) --
            BS (list) --An attribute of type Binary Set. For example:
            'BS': ['U3Vubnk=', 'UmFpbnk=', 'U25vd3k=']
            (bytes) --
            M (dict) --An attribute of type Map. For example:
            'M': {'Name': {'S': 'Joe'}, 'Age': {'N': '35'}}
            (string) --
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            
            L (list) --An attribute of type List. For example:
            'L': ['Cookies', 'Coffee', 3.14159]
            (dict) --Represents the data for an attribute.
            Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
            For more information, see Data Types in the Amazon DynamoDB Developer Guide .
            NULL (boolean) --An attribute of type Null. For example:
            'NULL': true
            BOOL (boolean) --An attribute of type Boolean. For example:
            'BOOL': true
            
            
            
            
            

    :type ReturnConsumedCapacity: string
    :param ReturnConsumedCapacity: Determines the level of detail about provisioned throughput consumption that is returned in the response:
            INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
            TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
            NONE - No ConsumedCapacity details are included in the response.
            

    :type ReturnItemCollectionMetrics: string
    :param ReturnItemCollectionMetrics: Determines whether item collection metrics are returned. If set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.

    :rtype: dict
    :return: {
        'UnprocessedItems': {
            'string': [
                {
                    'PutRequest': {
                        'Item': {
                            'string': {
                                'S': 'string',
                                'N': 'string',
                                'B': b'bytes',
                                'SS': [
                                    'string',
                                ],
                                'NS': [
                                    'string',
                                ],
                                'BS': [
                                    b'bytes',
                                ],
                                'M': {
                                    'string': {'... recursive ...'}
                                },
                                'L': [
                                    {'... recursive ...'},
                                ],
                                'NULL': True|False,
                                'BOOL': True|False
                            }
                        }
                    },
                    'DeleteRequest': {
                        'Key': {
                            'string': {
                                'S': 'string',
                                'N': 'string',
                                'B': b'bytes',
                                'SS': [
                                    'string',
                                ],
                                'NS': [
                                    'string',
                                ],
                                'BS': [
                                    b'bytes',
                                ],
                                'M': {
                                    'string': {'... recursive ...'}
                                },
                                'L': [
                                    {'... recursive ...'},
                                ],
                                'NULL': True|False,
                                'BOOL': True|False
                            }
                        }
                    }
                },
            ]
        },
        'ItemCollectionMetrics': {
            'string': [
                {
                    'ItemCollectionKey': {
                        'string': {
                            'S': 'string',
                            'N': 'string',
                            'B': b'bytes',
                            'SS': [
                                'string',
                            ],
                            'NS': [
                                'string',
                            ],
                            'BS': [
                                b'bytes',
                            ],
                            'M': {
                                'string': {'... recursive ...'}
                            },
                            'L': [
                                {'... recursive ...'},
                            ],
                            'NULL': True|False,
                            'BOOL': True|False
                        }
                    },
                    'SizeEstimateRangeGB': [
                        123.0,
                    ]
                },
            ]
        },
        'ConsumedCapacity': [
            {
                'TableName': 'string',
                'CapacityUnits': 123.0,
                'Table': {
                    'CapacityUnits': 123.0
                },
                'LocalSecondaryIndexes': {
                    'string': {
                        'CapacityUnits': 123.0
                    }
                },
                'GlobalSecondaryIndexes': {
                    'string': {
                        'CapacityUnits': 123.0
                    }
                }
            },
        ]
    }
    
    
    :returns: 
    RequestItems (dict) -- [REQUIRED]
    A map of one or more table names and, for each table, a list of operations to be performed (DeleteRequest or PutRequest ). Each element in the map consists of the following:
    
    DeleteRequest - Perform a DeleteItem operation on the specified item. The item to be deleted is identified by a Key subelement:
    Key - A map of primary key attribute values that uniquely identify the ! item. Each entry in this map consists of an attribute name and an attribute value. For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
    
    
    PutRequest - Perform a PutItem operation on the specified item. The item to be put is identified by an Item subelement:
    Item - A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with a ValidationException exception. If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
    
    
    
    
    (string) --
    (list) --
    (dict) --Represents an operation to perform - either DeleteItem or PutItem . You can only request one of these operations, not both, in a single WriteRequest . If you do need to perform both of these operations, you will need to provide two separate WriteRequest objects.
    
    PutRequest (dict) --A request to perform a PutItem operation.
    
    Item (dict) -- [REQUIRED]A map of attribute name to attribute values, representing the primary key of an item to be processed by PutItem . All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema. If any attributes are present in the item which are part of an index key schema for the table, their types must match the index key schema.
    
    (string) --
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    S (string) --An attribute of type String. For example:
    
    "S": "Hello"
    
    N (string) --An attribute of type Number. For example:
    
    "N": "123.45"
    Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
    
    B (bytes) --An attribute of type Binary. For example:
    
    "B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
    
    SS (list) --An attribute of type String Set. For example:
    
    "SS": ["Giraffe", "Hippo" ,"Zebra"]
    
    (string) --
    
    
    NS (list) --An attribute of type Number Set. For example:
    
    "NS": ["42.2", "-19", "7.5", "3.14"]
    Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
    
    (string) --
    
    
    BS (list) --An attribute of type Binary Set. For example:
    
    "BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
    
    (bytes) --
    
    
    M (dict) --An attribute of type Map. For example:
    
    "M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
    
    (string) --
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    
    
    
    
    L (list) --An attribute of type List. For example:
    
    "L": ["Cookies", "Coffee", 3.14159]
    
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    
    
    NULL (boolean) --An attribute of type Null. For example:
    
    "NULL": true
    
    BOOL (boolean) --An attribute of type Boolean. For example:
    
    "BOOL": true
    
    
    
    
    
    
    
    
    
    DeleteRequest (dict) --A request to perform a DeleteItem operation.
    
    Key (dict) -- [REQUIRED]A map of attribute name to attribute values, representing the primary key of the item to delete. All of the table's primary key attributes must be specified, and their data types must match those of the table's key schema.
    
    (string) --
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    S (string) --An attribute of type String. For example:
    
    "S": "Hello"
    
    N (string) --An attribute of type Number. For example:
    
    "N": "123.45"
    Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
    
    B (bytes) --An attribute of type Binary. For example:
    
    "B": "dGhpcyB0ZXh0IGlzIGJhc2U2NC1lbmNvZGVk"
    
    SS (list) --An attribute of type String Set. For example:
    
    "SS": ["Giraffe", "Hippo" ,"Zebra"]
    
    (string) --
    
    
    NS (list) --An attribute of type Number Set. For example:
    
    "NS": ["42.2", "-19", "7.5", "3.14"]
    Numbers are sent across the network to DynamoDB as strings, to maximize compatibility across languages and libraries. However, DynamoDB treats them as number type attributes for mathematical operations.
    
    (string) --
    
    
    BS (list) --An attribute of type Binary Set. For example:
    
    "BS": ["U3Vubnk=", "UmFpbnk=", "U25vd3k="]
    
    (bytes) --
    
    
    M (dict) --An attribute of type Map. For example:
    
    "M": {"Name": {"S": "Joe"}, "Age": {"N": "35"}}
    
    (string) --
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    
    
    
    
    L (list) --An attribute of type List. For example:
    
    "L": ["Cookies", "Coffee", 3.14159]
    
    (dict) --Represents the data for an attribute.
    Each attribute value is described as a name-value pair. The name is the data type, and the value is the data itself.
    For more information, see Data Types in the Amazon DynamoDB Developer Guide .
    
    
    
    NULL (boolean) --An attribute of type Null. For example:
    
    "NULL": true
    
    BOOL (boolean) --An attribute of type Boolean. For example:
    
    "BOOL": true
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    ReturnConsumedCapacity (string) -- Determines the level of detail about provisioned throughput consumption that is returned in the response:
    
    INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed. Note that some operations, such as GetItem and BatchGetItem , do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).
    TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.
    NONE - No ConsumedCapacity details are included in the response.
    
    
    ReturnItemCollectionMetrics (string) -- Determines whether item collection metrics are returned. If set to SIZE , the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.
    
    """
    pass
