Upload or put object in S3 failing silently

I’ve been trying to upload files from a local folder into folders on S3 using Boto3, and it’s failing kinda silently, with no indication of why the upload isn’t happening.

key_name = folder + '/' 
 s3_connect = boto3.client('s3', s3_bucket_region,)
 # upload File to S3
 for filename in os.listdir(folder):
     s3_name = key_name + filename
     print folder, filename, key_name, s3_name
     upload = s3_connect.upload_file(
         s3_name, s3_bucket, key_name,
     )

Printing upload just says “None”, with no other information. No upload happens. I’ve also tried using put_object:

put_obj = s3_connect.put_object(
        Bucket=s3_bucket, 
        Key=key_name,
        Body=s3_name,
    )

and I get an HTTPS response code of 200 - but no files upload.

First, I’d love to solve this problem, but second, it seems this isn’t the right behavior - if an upload doesn’t happen, there should be a bit more information about why (although I imagine this might be a limitation of the API?)

[bluppfisk]

Having a leading slash in your path to the object will create a folder with a blank name in your bucket root, which holds the uploads. e.g.:

path = "/uploads/"
s3.Object(my_bucket, path + filename).put(Body=data)

will create / /uploads in your bucket root (note the blank folder) and put the object in there rather than in /uploads. Since boto was also spamming the bucket root with odd files, I didn’t notice the empty folder until much later and lost a lot of time. Could be your problem, too?

[maxpearl]

So just for your information (and perhaps this will help someone figure out what’s up,) using the Service Resource instead of the client works fine. The upload into S3 “folders” works perfectly. Here’s some example code:

import boto3

testfile = 'test.csv'
bucket_name = 'bucket-name-here'
folder_name = 'folder-name'

key = folder_name + '/' + testfile
s3 = boto3.resource('s3')
bucket = s3.Bucket(bucket_name)

bucket.upload_file(testfile, key)

So at least there is a workaround for the problem with the client.