Almighty Bus Error

In Python, to create and maintain a FTP communication, the ftplib or urllib (explained in a future post) can be used.

Creating a FTP connection

from ftplib import FTP
try:
    conn = FTP('almightybuserror.com')
except:
    print "Could not connect to almightybuserror.com."
    return

Logging in…

For anonymous log in:

try:
    conn.login()
except:
    print "No anonymous connections allowed."
    return

Otherwise:

try:
    conn.login(user, passwd)
    print conn.getwelcome()
except:
    print "Wrong username or password."
    return

Sending commands and handling response.

To send commands (or requests) to the server there is a method for each command which can be consulted here, however I will show an example of an binary file download request.

try:
    conn.cwd('/stuff/more/misc/stuff/')
except:
    print "No such folder!"
    return
file = open('stuff', 'w')
try: # file.write acts as a function pointer
    conn.retrbinary('RETR stuff', file.write) 
except:
    print "Couldn't download stuff..."
finally:
    file.close()

Check downloader.py in github for a more complete example.