Python and DynamoDBAmit JoshiBlockedUnblockFollowFollowingMay 6In this tutorial, you use the AWS SDK for Python (Boto 3) to write simple programs to perform the following Amazon DynamoDB operations:Install DynamoDB LocalTable Creation for DynamoDB LocalPerform create, read, update, and delete operations on the table.
Run simple queries.
Getting started with Boto 3 is easy, but requires a few steps.
1.
Install Pluginnpm install -g serverless2.
Installation Boto3Install the latest Boto 3 release via pip:pip install boto3You may also install a specific version:pip install boto3==1.
0.
03.
Install aws CLIpip install awscli — upgrade — user4.
ConfigurationBefore you can begin using Boto 3, you should set up authentication credentials.
Credentials for your AWS account can be found in the IAM Console.
You can create or use an existing user.
Go to manage access keys and generate a new set of keys.
If you have the AWS CLI installed, then you can use it to configure your credentials file:aws configureAlternatively, you can create the credential file yourself.
By default, its location is at ~/.
aws/credentials:aws_access_key_id = YOUR_ACCESS_KEYaws_secret_access_key = YOUR_SECRET_KEYYou may also want to set a default region.
This can be done in the configuration file.
By default, its location is at ~/.
aws/config:region=us-east-1Alternatively, you can pass a region_name when creating clients and resources.
5.
Using Boto 3To use Boto 3, you must first import it and tell it what service you are going to use:import boto3# Let's use Amazon dynamodbclient = boto3.
client('dynamodb'))5.
1 Creating a New TableIn order to create a new table, use the DynamoDB.
ServiceResource.
create_table() methodimport boto3# Get the service resource.
dynamodb = boto3.
resource('dynamodb')# Create the DynamoDB table.
table = dynamodb.
create_table( TableName='users', KeySchema=[ { 'AttributeName': 'username', 'KeyType': 'HASH' }, { 'AttributeName': 'last_name', 'KeyType': 'RANGE' } ], AttributeDefinitions=[ { 'AttributeName': 'username', 'AttributeType': 'S' }, { 'AttributeName': 'last_name', 'AttributeType': 'S' }, ], ProvisionedThroughput={ 'ReadCapacityUnits': 5, 'WriteCapacityUnits': 5 })# Wait until the table exists.
table.
meta.
client.
get_waiter('table_exists').
wait(TableName='users')# Print out some data about the table.
print(table.
item_count)This creates a table named users that respectively has the hash and range primary keys username and last_name.
This method will return a DynamoDB.
Table resource to call additional methods on the created table.
5.
2 Using an Existing TableIt is also possible to create a DynamoDB.
Table resource from an existing table:import boto3# Get the service resource.
dynamodb = boto3.
resource('dynamodb')# Instantiate a table resource object without actually# creating a DynamoDB table.
Note that the attributes of this table# are lazy-loaded: a request is not made nor are the attribute# values populated until the attributes# on the table resource are accessed or its load() method is called.
table = dynamodb.
Table('users')# Print out some data about the table.
# This will cause a request to be made to DynamoDB and its attribute# values will be set based on the response.
print(table.
creation_date_time)Expected Output (Please note that the actual times will probably not match up):2015-06-26 12:42:45.
149000-07:005.
3 Creating a New ItemOnce you have a DynamoDB.
Table resource you can add new items to the table using DynamoDB.
Table.
put_item():table.
put_item( Item={ 'username': 'janedoe', 'first_name': 'Jane', 'last_name': 'Doe', 'age': 25, 'account_type': 'standard_user', })For all of the valid types that can be used for an item, refer to Valid DynamoDB Types.
5.
4 Getting an ItemYou can then retrieve the object using DynamoDB.
Table.
get_item():response = table.
get_item( Key={ 'username': 'janedoe', 'last_name': 'Doe' })item = response['Item']print(item)Expected Output:{u'username': u'janedoe', u'first_name': u'Jane', u'last_name': u'Doe', u'account_type': u'standard_user', u'age': Decimal('25')}5.
5 Updating ItemYou can then update attributes of the item in the table:table.
update_item( Key={ 'username': 'janedoe', 'last_name': 'Doe' }, UpdateExpression='SET age = :val1', ExpressionAttributeValues={ ':val1': 26 })Then if you retrieve the item again, it will be updated appropriately:response = table.
get_item( Key={ 'username': 'janedoe', 'last_name': 'Doe' })item = response['Item']print(item)Expected Output:{u'username': u'janedoe', u'first_name': u'Jane', u'last_name': u'Doe', u'account_type': u'standard_user', u'age': Decimal('26')}5.
6 Deleting ItemYou can also delete the item using DynamoDB.
Table.
delete_item():table.
delete_item( Key={ 'username': 'janedoe', 'last_name': 'Doe' })5.
7 Deleting a TableFinally, if you want to delete your table call DynamoDB.
Table.
delete():table.
delete().