Downloading file with pysftp

Question

I'm trying to load (and directly save locally) a .csv file stored on a FTP Server (SFTP protocol). I'm using Python in combination with pysftp library. When I check if the file exists, it returns TRUE. But when trying to load the file, it seems to be empty, whatever I try.

How can I get (and store) the file to my local environment? Do I miss something obvious?

import pysftp

cnopts = pysftp.CnOpts()
cnopts.hostkeys = None

# Make connection to sFTP
with pysftp.Connection(hostname,
                       username=sftp_username,
                       password=sftp_pw,
                       cnopts = cnopts
                       ) as sftp:
    sftp.isfile('directory/file.csv')) ## TRUE
    file = sftp.get('directory/file.csv')
    print(file) ## None

sftp.close()

Solution

Connection.get does not return anything. It downloads the remote file to a local path specified by the localpath argument. If you do not specify the argument, it downloads the file to the current working directory.

So if you want to download to a specific local directory instead, you want this:

sftp.get('directory/file.csv', '/local/path/file.csv')

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If you really want to read the file to a variable (what I understand that you actually do not want), you need to use Connection.getfo, like:

flo = BytesIO()
sftp.getfo(remotepath, flo)
flo.seek(0)

Alternatively, use Paramiko library directly (without the pysftp wrapper).
See Read a file from server with SSH using Python.

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Obligatory warning: Do not set cnopts.hostkeys = None, unless you do not care about security. For the correct solution see Verify host key with pysftp.