How to scp in python?

Question

What's the most pythonic way to scp a file in Python? The only route I'm aware of is

os.system('scp "%s" "%s:%s"' % (localfile, remotehost, remotefile) )

which is a hack, and which doesn't work outside linux-like systems, and which needs help from the Pexpect module to avoid password prompts unless you already have passwordless SSH set up to the remote host.

I'm aware of Twisted's conch, but I'd prefer to avoid implementing scp myself via low-level ssh modules.

I'm aware of paramiko, a Python module that supports ssh and sftp; but it doesn't support scp.

Background: I'm connecting to a router which doesn't support sftp but does support ssh/scp, so sftp isn't an option.

EDIT: This is a duplicate of How to copy a file to a remote server in Python using SCP or SSH?. However, that question doesn't give an scp-specific answer that deals with keys from within python. I'm hoping for a way to run code kind of like

import scp

client = scp.Client(host=host, user=user, keyfile=keyfile)
# or
client = scp.Client(host=host, user=user)
client.use_system_keys()
# or
client = scp.Client(host=host, user=user, password=password)

# and then
client.transfer('/etc/local/filename', '/etc/remote/filename')

Answer 1

I don't think there's any one module that you can easily download to implement scp, however you might find this helpful: http://www.ibm.com/developerworks/linux/library/l-twist4.html