Created
June 5, 2017 19:40
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scan all elements from a dynamodb table using Python (boto3)
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from __future__ import print_function # Python 2/3 compatibility | |
import boto3 | |
import json | |
import decimal | |
from boto3.dynamodb.conditions import Key, Attr | |
# Helper class to convert a DynamoDB item to JSON. | |
class DecimalEncoder(json.JSONEncoder): | |
def default(self, o): | |
if isinstance(o, decimal.Decimal): | |
if o % 1 > 0: | |
return float(o) | |
else: | |
return int(o) | |
return super(DecimalEncoder, self).default(o) | |
dynamodb = boto3.resource('dynamodb') # may require parameters if not using default AWS environment vars | |
table = dynamodb.Table('Movies') | |
fe = Key('year').between(1950, 1959); | |
pe = "#yr, title, info.rating" | |
# Expression Attribute Names for Projection Expression only. | |
ean = { "#yr": "year", } # aliases for reserved keywords | |
# http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html | |
esk = None | |
response = table.scan( | |
FilterExpression=fe, | |
ProjectionExpression=pe, | |
ExpressionAttributeNames=ean | |
) | |
for i in response['Items']: | |
print(json.dumps(i, cls=DecimalEncoder)) | |
# or do something else, like items.append(i) | |
while 'LastEvaluatedKey' in response: | |
response = table.scan( | |
ProjectionExpression=pe, | |
FilterExpression=fe, | |
ExpressionAttributeNames= ean, | |
ExclusiveStartKey=response['LastEvaluatedKey'] | |
) | |
for i in response['Items']: | |
print(json.dumps(i, cls=DecimalEncoder)) | |
# or do something else, like items.append(i) |
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Thank you so much. It worked great.