Add ability to disable Decimal usage for DynamoDB number type.

Hi,

Is there any strong reason why using a DynamoDB’s Table resource will convert the number type "N" to a Decimal() object?

Shouldn’t it try looking up the right python type, such as int or float or long?

I am trying to unpack a record’s data (a mapping) into a function call, specifically: next_execution = now() + datetime.timedelta(**dynamo_record['frequency']) but datetime.timedelta will not accept the Decimal object into its arguments, although it does accept long and float.

TypeError: unsupported type for timedelta days component: Decimal

[garnaat]

FWIW, I use this little function to recurse into Python objects returned by the boto3 DynamoDB resource layer and convert any Decimal values to int or float. It is by no means foolproof and doesn’t in any way solve the problem of lack of precision in Python’s float type but it solves my problem which is mainly to turn the data into something that can be returned to API Gateway via a Python Lambda function.

def replace_decimals(obj):
    if isinstance(obj, list):
        for i in xrange(len(obj)):
            obj[i] = replace_decimals(obj[i])
        return obj
    elif isinstance(obj, dict):
        for k in obj.iterkeys():
            obj[k] = replace_decimals(obj[k])
        return obj
    elif isinstance(obj, decimal.Decimal):
        if obj % 1 == 0:
            return int(obj)
        else:
            return float(obj)
    else:
        return obj

[jamesls]

Would adding some sort of use_decimal=False option to the config object when creating clients/resources be helpful?