Python FTW: Clearing an FTP folder.

I'm doing some testing that involves kicking off a lot of concurrent processes. Some of these write files to an FTP server. I don't need those files once I've checked that they exist, but FTP doesn't allow deletion of multiple files (AFAIK). The first time we cleared the server, we took a directory listing and wrote an FTP script from that. It worked well enough, but we'd need to write that script each time.

So a little play with Python gave me this...

from ftplib import FTP

def clearFTPDirectory(address,
                    username,
                    directory):

  server=FTP(address)
  server.login(username)
  server.cwd(directory)

  directory=[]
  server.dir(directory.append)

  # list comprehension, baby!
  filenames=[entry.split(':')[-1][3:] for entry in directory]

  for filename in filenames:
      try:
          server.delete(filename)
          print 'Deleted:%s'%filename
      except:
          print ('failed to delete "%s"'%filename)

  server.quit()

…it should save a fair few cumulative hours, but more importantly, it'll save a fair few hours of tedium.

The bit that tripped me up for a little while was server.dir(directory.append) which takes the append function as a parameter. Makes perfect sense now.

Note: if you use this, you may need to check the format of the strings returned by dir(), and adjust the line that extracts the filename.