Amazon S3 boto3 how to iterate through objects in a bucket?

In a flask app, I was trying to iterate through objects in a S3 Bucket and trying to print the key/ filename but my_bucket.objects.all() returns only the first object in the bucket. It’s not returning the all the objects. The output is [001.pdf] instead of [001, 002, 003, 004, 005]

from flask import Flask, jsonify, Response, request
from flask_cors import CORS, cross_origin
from config import S3_BUCKET, S3_ACCESS_KEY, S3_SECRET_ACCESS_KEY

import boto3
import csv
import re


s3 = boto3.client(
    's3',
    aws_access_key_id=S3_ACCESS_KEY,
    aws_secret_access_key=S3_SECRET_ACCESS_KEY
)

app = Flask(__name__)
CORS(app, supports_credentials=True)


@app.route('/')
def health():
    return jsonify({"message": "app is working"})


@app.route('/files')
def list_of_files():
    s3_resource = boto3.resource('s3')
    my_bucket = s3_resource.Bucket(S3_BUCKET)
    summaries = my_bucket.objects.all()
    files = []
    for file in summaries:
        # this prints the bucket object
        print("Object: {}".format(summaries))
        files.append(file.key)
        # file.key is supposed to return the names of the list of objects
        # print(file.key)
        return jsonify({"files":"{}".format(file.key)})




if __name__ == "__main__":
    app.run()

Answer

You are exiting the loop by returning too early.

def list_of_files():
    s3_resource = boto3.resource('s3')
    my_bucket = s3_resource.Bucket(S3_BUCKET)
    summaries = my_bucket.objects.all()
    files = []
    for file in summaries:
        files.append(file.key)
    return jsonify({"files": files})