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DynamoDB  >  Operations  >  put_item

put_item

Operation

put_item async 

put_item(input: PutItemInput, plugins: list[Plugin] | None = None) -> PutItemOutput

Creates a new item, or replaces an old item with a new item. If an item that has the same primary key as the new item already exists in the specified table, the new item completely replaces the existing item. You can perform a conditional put operation (add a new item if one with the specified primary key doesn't exist), or replace an existing item if it has certain attribute values. You can return the item's attribute values in the same operation, using the ReturnValues parameter.

When you add an item, the primary key attributes are the only required attributes.

Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index. Set type attributes cannot be empty.

Invalid Requests with empty values will be rejected with a ValidationException exception.

Note

To prevent a new item from replacing an existing item, use a conditional expression that contains the attribute_not_exists function with the name of the attribute being used as the partition key for the table. Since every record must contain that attribute, the attribute_not_exists function will only succeed if no matching item exists.

Note: To determine whether PutItem overwrote an existing item, use ReturnValues set to ALL_OLD. If the response includes the Attributes element, an existing item was overwritten.

For more information about PutItem, see Working with Items in the Amazon DynamoDB Developer Guide.

Parameters:

Name Type Description Default
input PutItemInput

An instance of PutItemInput.

 required
plugins list[Plugin] | None

A list of callables that modify the configuration dynamically. Changes made by these plugins only apply for the duration of the operation execution and will not affect any other operation invocations.

 None

Returns:

Type Description
PutItemOutput

An instance of PutItemOutput.

Input

PutItemInput dataclass

Represents the input of a PutItem operation.

Attributes

condition_expression class-attribute instance-attribute 
condition_expression: str | None = None

A condition that must be satisfied in order for a conditional PutItem operation to succeed.

An expression can contain any of the following:

  • Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

These function names are case-sensitive.

  • Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN

  • Logical operators: AND | OR | NOT

For more information on condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.

conditional_operator class-attribute instance-attribute 
conditional_operator: ConditionalOperator | None = None

This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

expected class-attribute instance-attribute 
expected: dict[str, ExpectedAttributeValue] | None = None

This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

expression_attribute_names class-attribute instance-attribute 
expression_attribute_names: dict[str, str] | None = None

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

  • To access an attribute whose name conflicts with a DynamoDB reserved word.

  • To create a placeholder for repeating occurrences of an attribute name in an expression.

  • To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

  • Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

  • {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

  • #P = :val
Note

Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

expression_attribute_values class-attribute instance-attribute 
expression_attribute_values: dict[str, AttributeValue] | None = None

One or more values that can be substituted in an expression.

Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

Available | Backordered | Discontinued

You would first need to specify ExpressionAttributeValues as follows:

{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }

You could then use these values in an expression, such as this:

ProductStatus IN (:avail, :back, :disc)

For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

item class-attribute instance-attribute 
item: dict[str, AttributeValue] | None = None

A map of attribute name/value pairs, one for each attribute. Only the primary key attributes are required; you can optionally provide other attribute name-value pairs for the item.

You must provide all of the attributes for the primary key. 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 both values for both the partition key and the sort key.

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.

If the table has vector indexes, the following validations apply to write operations. A violation of any of these constraints results in a ValidationException:

  • The vector attribute must be a list of numbers with dimensions matching the index configuration.

  • Vector values must fit in 32-bit IEEE-754 floating point format (f32).

  • Partition key and inline filter attributes defined in the search schema must have data types matching the index schema definition.

Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index.

For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide.

Each element in the Item map is an AttributeValue object.

return_consumed_capacity class-attribute instance-attribute 
return_consumed_capacity: ReturnConsumedCapacity | None = None

Determines the level of detail about either provisioned or on-demand 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.

return_item_collection_metrics class-attribute instance-attribute 
return_item_collection_metrics: ReturnItemCollectionMetrics | None = None

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.

return_values class-attribute instance-attribute 
return_values: ReturnValue | None = None

Use ReturnValues if you want to get the item attributes as they appeared before they were updated with the PutItem request. For PutItem, the valid values are:

  • NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)

  • ALL_OLD - If PutItem overwrote an attribute name-value pair, then the content of the old item is returned.

The values returned are strongly consistent.

There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.

Note

The ReturnValues parameter is used by several DynamoDB operations; however, PutItem does not recognize any values other than NONE or ALL_OLD.

return_values_on_condition_check_failure class-attribute instance-attribute 
return_values_on_condition_check_failure: ReturnValuesOnConditionCheckFailure | None = None

An optional parameter that returns the item attributes for a PutItem operation that failed a condition check.

There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.

table_name class-attribute instance-attribute 
table_name: str | None = None

The name of the table to contain the item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

Output

PutItemOutput dataclass

Represents the output of a PutItem operation.

Attributes

attributes class-attribute instance-attribute 
attributes: dict[str, AttributeValue] | None = None

The attribute values as they appeared before the PutItem operation, but only if ReturnValues is specified as ALL_OLD in the request. Each element consists of an attribute name and an attribute value.

consumed_capacity class-attribute instance-attribute 
consumed_capacity: ConsumedCapacity | None = None

The capacity units consumed by the PutItem operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Capacity unity consumption for write operations in the Amazon DynamoDB Developer Guide.

If the table has vector indexes, the response includes a VectorIndexes field with VectorWriteRequestBytes consumed for each affected vector index.

item_collection_metrics class-attribute instance-attribute 
item_collection_metrics: ItemCollectionMetrics | None = None

Information about item collections, if any, that were affected by the PutItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response.

Each ItemCollectionMetrics element consists of:

  • ItemCollectionKey - The partition key value of the item collection. This is the same as the partition key value of the item itself.

  • SizeEstimateRangeGB - An estimate of item collection size, in gigabytes. This value is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on that table. Use this estimate to measure whether a local secondary index is approaching its size limit.

The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.