Fetch multiple filename from S3 and append in a list to print the same in output

Question

I have multiple files uploaded in S3 bucket and I want to print the names of the files in the output in a list through lamda python .

Lets say I have files S1,S2,S3 ... and so on and I want the output as ['S1','S2','S3'..] for all the files uploaded in S3.

I have tried code like below but not able to print the output as expected :-

import boto3
import json
from datetime import datetime as dt

client = boto3.resource('s3')
s3_client = boto3.client('s3')
def lambda_handler(event, context):
    paginator = s3_client.get_paginator('list_objects')

    # Create a PageIterator from the Paginator
    page_iterator = paginator.paginate(Bucket='mylocals3bucketpoc')
    for page in page_iterator:
    vars = []
        for Contents in page['Contents']:
            print(Contents['Key'])
      

The output :-

S1
S2
S3

as I want to have the output like ['S1','S2','S3'] ,I am trying to use list append but not able to get desired output. Please help me to resolve the same.

Answer 1

You can create a list and append your names to it.

import boto3
import json
from datetime import datetime as dt

client = boto3.resource('s3')
s3_client = boto3.client('s3')

def lambda_handler(event, context):
    paginator = s3_client.get_paginator('list_objects')
    page_iterator = paginator.paginate(Bucket='mylocals3bucketpoc')
    file_list = []

    for page in page_iterator:
        for Contents in page['Contents']:
            file_list.append(Contents['Key'])
    print(file_list)

Or simple list comperehension.

file_list = [content['Key'] for page in page_iterator for content in page['Contents']]