IO Error in boto3 download_file

Error raised because you attempted to download and save file into directory which not exists. Use os.mkdir prior downloading file to create an directory.

# ...
else:
    item_uuid = str(uuid.uuid4())
    os.mkdir('/tmp/{}'.format(item_uuid))
    download_path = '/tmp/{}/{}'.format(item_uuid, key)  # File is uploaded inside a folder

Note: It's better to use os.path.join() while operating with systems paths. So code above could be rewritten to:

# ...
else:
    item_uuid = str(uuid.uuid4())
    os.mkdir(os.path.join(['tmp', item_uuid]))
    download_path = os.path.join(['tmp', item_uuid, key]))

Also error may be raises because you including '/tmp/' in download path for s3 bucket file, do not include tmp folder as likely it's not exists on s3. Ensure you are on the right way by using that articles:

• Amazon S3 upload and download using Python/Django

• Python s3 examples

I faced the same issue, and the error message caused a lot of confusion, (the random string extension after the file name). In my case it was caused by the missing directory path, which didn't exist.