Decimal encoder to use with json.dumps so that it handles Decimals (by converting them to floats)

decimalencoder.py

class DecimalEncoder(json.JSONEncoder):
    '''
    An encoder for use with json.dumps when the dict contains Decimal type objects
    such as are returned for DynamoDB number attributes.
    Usage: json.dumps(someDict, cls=DecimalEncoder)
    '''
    def default(self, o):
        if isinstance(o, decimal.Decimal):
            return float(o)
        return super(DecimalEncoder, self).default(o)