This recipe takes a few command-line inputs: the remote hostname, server port, source filename, and destination filename. For the sake of simplicity, we can use default or hard-coded values for these input parameters.

In order to connect to the remote host, we need the username and password, which can be obtained from the user from the command line.

Listing 6.2 explains how to copy a file remotely by SFTP, as shown in the following code:

#!/usr/bin/env python 
# Python Network Programming Cookbook, Second Edition -- Chapter - 6 
# This program is optimized for Python 3.5.2. 
# It may run on any other version with/without modifications. 
# To make it run on Python 2.7.x, needs some changes due to API differences. 
# Follow the comments inline to make the program work with Python 2. 
 
 
import argparse 
import paramiko 
import getpass 
 
 
SOURCE = '6_2_copy_remote_file_over_sftp.py'  
DESTINATION ='/tmp/6_2_copy_remote_file_over_sftp.py ' 
 
 
def copy_file(hostname, port, username, password, src, dst): 
    client = paramiko.SSHClient() 
    client.load_system_host_keys() 
    print (" Connecting to %s 
 with username=%s...
              
" %(hostname,username)) 
    t = paramiko.Transport(hostname, port) 
    t.connect(username=username,password=password) 
    sftp = paramiko.SFTPClient.from_transport(t) 
    print ("Copying file: %s to path: %s" %(src, dst)) 
    sftp.put(src, dst) 
    sftp.close() 
    t.close() 
 
 
if __name__ == '__main__': 
    parser = argparse.ArgumentParser(description='Remote file copy') 
    parser.add_argument('--host', action="store",
                        dest="host", default='localhost') 
    parser.add_argument('--port', action="store",
                        dest="port", default=22, type=int) 
    parser.add_argument('--src', action="store",
                        dest="src", default=SOURCE) 
    parser.add_argument('--dst', action="store",
                        dest="dst", default=DESTINATION) 
     
    given_args = parser.parse_args() 
    hostname, port =  given_args.host, given_args.port 
    src, dst = given_args.src, given_args.dst 
     
    user = input("Enter your remote account: ") 
    # Comment out the above line and uncomment the 
      below line for Python 2.7. 
    # user = raw_input("Enter your remote account: ") 
 
    password = getpass.getpass("Enter password for %s: " %user) 
     
    copy_file(hostname, port, user, password, src, dst) 
 

If you run this script, you will see an output similar to the following:

$ python3 6_2_copy_remote_file_over_sftp.py 
Enter your remote account: pradeeban
Enter password for pradeeban: 
 Connecting to localhost 
 with username=pradeeban... 
    
Copying file: 6_2_copy_remote_file_over_sftp.py to path: /tmp/6_2_copy_remote_file_over_sftp.py