ftplib checking if a file is a folder?

Question

How can i check if a file on a remote ftp is a folder or not using ftplib?

Best way i have right now is to do a nlst, and iterate through calling size on each of the files, if the file errors out then it is a folder?

Is there a better way? I cannot parse the output of list, since there is about a dozen different ftp servers(many extremely old.)

What should i do?

Answer 1

FTP.dir returns a directory listing, that you can parse with a callback function to find out whether it's a directory. For example, like this:

def parse(line):
    if line[0] == 'd':
        print(line.rpartition(' ')[2])   # gives you the name of a directory

ftp.dir(parse)

Answer 2

def is_file(filename):
    return ftp.size(filename) is not None

This works because ftp.size returns None if it is a directory.

Answer 3

def is_file(filename):
    current = ftp.pwd()
    try:
        ftp.cwd(filename)
    except:
        ftp.cwd(current)
        return True
    ftp.cwd(current)
    return False

Here is another solution. Half way writing it out I realized it has a problem. If you don't have permission to change to a folder, it'll read it as a file instead. It'll work if you have access to any folder.

I still posted it because maybe it'll give some ideas.

Answer 4

FTP is quite a rudimentary protocol and there's no built-in protocol query allowing you to get the type (file, dir) of each node, so a heuristic like the one you found is the only solution.

If getting the size of each node doesn't work, perhaps you should consider calling FTP.nlst() on each of those nodes: those that error out will be files rather than dirs.

Answer 5

I'm running into this concern now too. I suppose no more progress has been made? Also I'm wondering if an sftp solution is available yet.