在 Dynamodb Python 查询中捕获异常

Question

我正在尝试使用分区键从 dynamodb 获取值，如果找到分区键值，代码工作正常。但是当找不到分区键时会抛出异常并且不会被捕获。

在代码中，我使用了自定义层 d_c_fun，其中定义了记录器功能。我已经尝试过具有以下逻辑的 elseif 函数。如果找到分区键 "data_id"，则正确返回值。但是当键值不存在时，它会抛出错误，而不是像下面的异常块那样给出响应。

import json
import boto3
import logging
import d_c_fun as cf

LOGGER = cf.get_logger()
dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('tablename')
def lambda_handler(event, context):

    LOGGER.lambda_init(event, context)
    # Event value received through trigger

    D_Id = event['D_Id']
    if not D_Id:
        raise Exception ("data_id value not passed")
        #LOGGER.error(""data_id value not passed"")
    elif D_Id :
        resp = table.get_item(Key={
        "data_id":D_Id})
        LOGGER.info("Response Output value for the %s: %s", D_Id, resp['Item'])
        return resp['Item']
    else:
        raise Exception ("The data_id - %s provided doesn't exist in db", D_Id)

1）o/p：当data_id在table中匹配时如下。

输入事件

{ "D_Id": "data2" }

代码输出：

{ "table_name": "data2", "data_id": "data2" }

2）o/p：当data_id不匹配时table如下。

输入事件值：

{ "D_Id": "data" }

代码输出：

{ "errorMessage": "'Item'", "errorType": "KeyError",
"stackTrace": [ " File \"/var/task/demo.py\", line 23, in lambda_handler\n LOGGER.info(\"Response Output value for the %s: %s\", D_Id, resp['Item'])\n" ] }

预期o/p是为了防止data_id不匹配。

data_id - 数据库中不存在提供的数据。

3）o/p：当data_id作为空值传递时。

输入事件值：

{ "D_Id": "" }

代码输出：

{ "errorMessage": "data_id value not passed", "errorType": "Exception", "stackTrace": [ " File \"/var/task/demo.py\", line 18, in lambda_handler\n raise Exception (\"data_id not set\")\n" ] }

预期输出应该是。

"errorMessage": "data_id value not passed",

Answer 1

我原来的回答完全不是你的目的。试试这个。

import json
import boto3
import logging
import d_c_fun as cf

LOGGER = cf.get_logger()
dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('tablename')
def lambda_handler(event, context):

    LOGGER.lambda_init(event, context)
    # Event value received through trigger

    D_Id = event['D_Id']
    if not D_Id:
        raise Exception ("data_id value not passed")
        #LOGGER.error(""data_id value not passed"")
    else:
        try:
            resp = table.get_item(Key={"data_id":D_Id})
            LOGGER.info("Response Output value for the %s: %s", D_Id, resp['Item'])
            return resp['Item']
        except:
            raise Exception ("The data_id - %s provided doesn't exist in db", D_Id)

Answer 2

我也开发了这段代码并且它按预期工作:)。

    import json
    import boto3
    import logging
    from botocore.exceptions import ClientError

    import d_c_fun as cf

    LOGGER = cf.get_logger()
    def get_dynamodb_client():
    dynamodb = boto3.client('dynamodb', region_name='REGION_NAME')
    return dynamodb


    def get_dynamodb_resource():
    dynamodb = boto3.resource('dynamodb', region_name='REGION_NAME')
    return dynamodb   


    def lambda_handler(event, context):
    D_Id = event['D_Id']

    if not D_Id:
        raise NameError("Field data_id is empty, Please enter data_id")
        return resp['Item']

    resp = get_dynamodb_resource().Table("TABLE_NAME").get_item(Key={
            "data_id":D_Id})

    if 'Item' not in resp:
        raise KeyError(
                'Data "{}" not found. '.format(D_Id) +
                'Please enter valid data_id.'
            )
        return resp['Item']
   else:
       LOGGER.info("Got the Item Successfully - \n %s", resp['Item'])
       return resp['Item']

在 Dynamodb Python 查询中捕获异常

Catching Exception in Dynamodb Python query

amazon-dynamodb

boto3

aws-lambda

dynamodb-queries