python - AWS Lambda 中缺少处理程序错误

Question

对于基本问题，我深表歉意。我是 AWS 和 Python 的新手。我正在尝试执行 https://boto3.readthedocs.io/en/latest/guide/migrations3.html#accessing-a-bucket 中给出的示例代码但遇到错误。

import botocore
import boto3
s3 = boto3.resource('s3')
bucket = s3.Bucket('bucketname')
exists = True


try:
    s3.meta.client.head_bucket(Bucket='bucketname')
except botocore.exceptions.ClientError as e:
    # If a client error is thrown, then check that it was a 404 error.
    # If it was a 404 error, then the bucket does not exist.
    error_code = int(e.response['Error']['Code'])
    if error_code == 404:
        exists = False 

日志中的错误是

"errorMessage": "Handler 'lambda_handler' missing on module 'lambda_function'"

Answer 1

您需要在代码中定义一个函数。该代码缺少名为 lambda_handler 的函数。您的代码应如下所示:

    import botocore
    import boto3

    def lambda_handler(event, context):
        s3 = boto3.resource('s3')
        bucket = s3.Bucket('bucketname')
        exists = True

        try:
            s3.meta.client.head_bucket(Bucket='bucketname')
        except botocore.exceptions.ClientError as e:
            # If a client error is thrown, then check that it was a 404 error.
            # If it was a 404 error, then the bucket does not exist.
            error_code = int(e.response['Error']['Code'])
            if error_code == 404:
                exists = False