Agfdhyk

I am using Paramiko to create an SFTP client to create a backup copy of a JSON file, read in the contents of the original, then update (the original). I am able to get this snippet of code to work:

# open sftp connection stuff



# read in json create backup copy - but have to 'open' twice

read_file = sftp_client.open(file_path)

settings = json.load(read_file)

read_file = sftp_client.open(file_path)  

sftp_client.putfo(read_file, backup_path)



# json stuff and updating

new_settings = json.dumps(settings, indent=4, sort_keys = True)



# update remote json file

with sftp_client.open(file_path, 'w') as f:

    f.write(new_settings)

However when I try to clean up the code and combine the backup file creation and JSON load:

with sftp_client.open(file_path) as f:

    sftp_client.putfo(f, backup_path)    

    settings = json.load(f)

The backup file will be created but json.load will fail to due not having any content. And if I reverse the order, the json.load will read in the values, but the backup copy will be empty.

I'm using Python 2.7 on a Windows machine, creating a remote connection to a QNX (Linux) machine. Appreciate any help.

Thanks in advance.

If you want to read the file second time, you have to seek file read pointer back to the file beginning:

with sftp_client.open(file_path) as f:

    sftp_client.putfo(f, backup_path)    

    f.seek(0, 0)

    settings = json.load(f)

Though that is functionally equivalent to your original code with two open's.

If you aim was to optimize the code, to avoid downloading the file twice, you will have to read/cache the file to memory and then upload and load the contents from the cache.

f = BytesIO()

sftp_client.getfo(file_path, f)

f.seek(0, 0)

sftp_client.putfo(f, backup_path)    

f.seek(0, 0)

settings = json.load(f)