Recursivly traverses a FTP directory, picking a random user-given number of files and outputting them in the format {image: http://<filename>}

ftppicker.py

"""
Recursivly traverses a FTP directory, picking a random user-given number of files and outputting them in the format
{image: http://<filename>}
"""
import ftplib
import random
from optparse import OptionParser

def traverse(ftp, depth=0):
    """
    return a recursive listing of an ftp server contents (starting
    from the current directory)

    listing is returned as a recursive dictionary, where each key
    contains a contents of the subdirectory or None if it corresponds
    to a file.

    @param ftp: ftplib.FTP object
    """
    level = {}
    for entry in (path for path in ftp.nlst() if path not in ('.', '..')):
        try:
            ftp.cwd(entry)
            level[entry] = traverse(ftp, depth+1)
            ftp.cwd('..')
        except ftplib.error_perm:
            level[entry] = None
    return level

FILES=[]


def process_dict(d, path=()):
  for k, v in d.iteritems():
    if not v: #if v is none, meaning k is a file
        FILES.append('/'.join(path) + '/' + k)
    else:
        process_dict(v, path + (k,))


usage = "usage: %prog [options] ip_address directory"
parser = OptionParser(usage=usage)
parser.add_option("-u", "--username", dest="username",
                  help="username for FTP account")
parser.add_option("-p", "--password", dest="password",
                  help="password for FTP account")
parser.add_option("-n", "--number", dest="number", type="int",
                  help="number of files to pick", default=30)
  			  
(options, args) = parser.parse_args()	
ftp = ftplib.FTP(args[0])
BASE_PATH=args[1]
ftp.connect()
try:
    ftp.login(options.username, options.password)
    ftp.set_pasv(True)
    ftp.cwd(BASE_PATH)
    recursiveFiles=traverse(ftp)
finally:
    ftp.quit()

FILES=[f for f in recursiveFiles.keys() if recursiveFiles[f] is None] #add files in current directory
for f in FILES: #and filter them out
    del recursiveFiles[f]
process_dict(recursiveFiles)
FILES=['http://localhost/' + BASE_PATH + f for f in FILES]
FILES=random.sample(FILES, options.number)
for f in FILES[:-1]:
    print '\t' * 14 + "{image : '%s'},\n" % f
print '\t' * 14 + "{image : '%s'}" % FILES[-1]