Batch photo renaming with FTP interaction

[brendan]

I'm trying to write a code that batch renames photos. In the end each photo should be named:

AABBB1111YYYYMM222 where

AABBB1111 defines a given place. (i.e. CAMTL = montreal and four digits define the area in Montreal.)

YYYYMM reveals the year and month that the photo was taken based on EXIF data.

222 allows for 999 photos of a given place in a given month.

That is to say, if there are three photos of the Olympic Stadium in Montreal taken in June 2008, the photos ought to be renamed to:

CAMTL8012200806001
CAMTL8012200806002
CAMTL8012200806003

BUT there is an FTP with a bunch of photos already uploaded. So say, hypothetically, someone had previously uploaded 3 photos of the Olympic Stadium in Montreal taken in June 2008. Then my pictures of the Olympic Stadium ought to be renamed to:

CAMTL8012200806004
CAMTL8012200806005
CAMTL8012200806006

This is where my program stops working. I can't figure out why my FTP interaction isn't working. I'm trying to search a folder in the FTP for pictures with the same first 15 digits as the file that's being renamed. If any exist, then I need to add 1 to the last three digits.

I'm kind of new to Python. Can anyone help me out? Here's my script:

# PHOTO RENAMER
 
import EXIF
import sys
import os
import string
import datetime
import ftplib
 
# FUNCTION DEFINITIONS
 
def date_from_exif(file):
   data = EXIF.process_file(file, details=False, debug=False)
   if not data or not data.has_key('EXIF DateTimeOriginal'):
      return False
   else:
      return str(data['EXIF DateTimeOriginal'])
 
def format_exif_date(date):
   name = date.replace(':', '')
   name = name.replace(' ', '')
   return name
 
def rename_image(filename):
   if not valid_image(filename):
      return
   try:
      file = open(filename, 'rb')
   except:
      print "'%s': Cannot open for reading.\n" % filename
      return
   date = date_from_exif(file)
   if (date == False):
      return
   file.close()
   newname = dir[-9:] + format_exif_date(date)
   ftpdir = ftp.nlst('testfolder/')
   return ftpdir
   same_month = list()
   for item in ftpdir:
      if item[:15] == newname:
         same_month.append(item)
      else:
         return
   return same_month
   if same_month == []:
      suffix = "001"
   else:
      suffix = same_month[-1]
      suffix = float(suffix[16:18])
      suffix = suffix + 1
      suffix = suffix.zfill(3)
      suffix = str(suffix)
   return suffix
   newname = newname + suffix + ".jpg"
   if os.path.exists(newname):
      print '[FAIL] ' + filename + ' already exists, ignoring...'
      return
   else:
      print filename + ' -> ' + newname
      os.rename(filename, newname)
 
def valid_image(filename):
   return string.lower(os.path.splitext(filename)[1]) in ['.jpg', '.jpeg']
 
# MAIN LOOP
 
dir = raw_input("Enter directory for image name conversion\n")
if not os.path.isdir(dir):
   print '"' + dir + '" is not a directory. Exiting...'
   exit()
 
os.chdir(dir)
files = os.listdir('.')
# confirm?
confirm = raw_input('Process ' + str(len(files)) + ' files in directory "' + dir + '"? [y/n]: ')
if string.lower(confirm) != 'y':
   print 'Exiting...'
   exit()
 
ftp = ftplib.FTP("www.****.******.ca")
ftp.login('******', '******')
 
for filename in files:
   rename_image(filename)
 
ftp.quit()