[PYTHON] Issue S3 time-limited URL with boto3 (with file existence confirmation)

You can issue a time-limited URL with generate_presigned_url, but there is a problem that you can also create a key for which the object does not exist. So I tried to issue a time-limited URL after checking if the object actually exists with get_object.

import boto3
import botocore
import logging
logger = logging.getLogger()

def create_presigned_url( bucket_name, key ):
	s3 = boto3.client('s3')
	try:
		s3.get_object(
			Bucket = bucket_name,
			Key = key
		)
		url = s3.generate_presigned_url(
			ClientMethod = 'get_object',
			Params = {
				Bucket = bucket_name,
				Key = key
			},
			ExpiresIn = 3600,
			HttpMethod = 'GET'
		)
		return url
	except botocore.exceptions.ClientError as e:
		logger.warning(e)
		return 'File ' + bucket_name + '/' + key + 'not found'
		

bucket_name = 'BUCKET_NAME'
key = 'S3_OBJECT_KEY'
create_presigned_url( bucket_name, key )
	

If you run get_object on an object that doesn't exist, you'll get a ClientError. So, if the object does not exist with try ~ except using it, the process is terminated without executing generate_presigned_url.