signed.py

import boto3

bucketname = "<BUCKET_NAME>"

s3 = boto3.resource('s3')
bucket = s3.Bucket(bucketname)

client = boto3.client('s3')

for obj in bucket.objects.all():
    url = client.generate_presigned_url(
        ClientMethod='get_object',
        Params={
                'Bucket': bucket.name,
                'Key': obj.key,
        },
        ExpiresIn=30
    )
    print url