SFTP in Python? (platform independent)

Paramiko supports SFTP. I've used it, and I've used Twisted. Both have their place, but you might find it easier to start with Paramiko.

You should check out pysftp https://pypi.python.org/pypi/pysftp it depends on paramiko, but wraps most common use cases to just a few lines of code.

import pysftp
import sys

path = './THETARGETDIRECTORY/' + sys.argv[1]    #hard-coded
localpath = sys.argv[1]

host = "THEHOST.com"                    #hard-coded
password = "THEPASSWORD"                #hard-coded
username = "THEUSERNAME"                #hard-coded

with pysftp.Connection(host, username=username, password=password) as sftp:
    sftp.put(localpath, path)

print 'Upload done.'

If you want easy and simple, you might also want to look at Fabric. It's an automated deployment tool like Ruby's Capistrano, but simpler and of course for Python. It's build on top of Paramiko.

You might not want to do 'automated deployment' but Fabric would suit your use case perfectly none the less. To show you how simple Fabric is: the fab file and command for your script would look like this (not tested, but 99% sure it will work):

fab_putfile.py:

from fabric.api import *

env.hosts = ['THEHOST.com']
env.user = 'THEUSER'
env.password = 'THEPASSWORD'

def put_file(file):
    put(file, './THETARGETDIRECTORY/') # it's copied into the target directory

Then run the file with the fab command:

fab -f fab_putfile.py put_file:file=./path/to/my/file

And you're done! :)