Determine if a listing is a directory or file in Python over FTP

Question

Python has a standard library module ftplib to run FTP communications. It has two means of getting a listing of directory contents. One, FTP.nlst()

Answer 1

Unfortunately FTP doesn't have a command to list just folders so parsing the results you get from ftp.dir() would be 'best'.

A simple app assuming a standard result from ls (not a windows ftp)

from ftplib import FTP

ftp = FTP(host, user, passwd)
for r in ftp.dir():
    if r.upper().startswith('D'):
        print r[58:]  # Starting point

Standard FTP Commands

Custom FTP Commands

Answer 2

If the FTP server supports the MLSD command, then please check that answer for a couple of useful classes (FTPDirectory and FTPTree).

Answer 3

Another way is to assume everything is a directory and try and change into it. If this succeeds it is a directory, but if this throws an ftplib.error_perm it is probably a file. You can catch then catch the exception. Sure, this isn't really the safest, but neither is parsing the crazy string for leading 'd's.

Example

def processRecursive(ftp,directory):
    ftp.cwd(directory)
    #put whatever you want to do in each directory here
    #when you have called processRecursive with a file, 
    #the command above will fail and you will return


    #get the files and directories contained in the current directory
    filenames = []
    ftp.retrlines('NLST',filenames.append)
    for name in filenames:
        try:
            processRecursive(ftp,name)
        except ftplib.error_perm:
            #put whatever you want to do with files here

    #put whatever you want to do after processing the files 
    #and sub-directories of a directory here