使用ftplib下载目录树

Question

这个方法无法下载子目录里的内容；我该怎么做才能下载呢？

import ftplib
import configparser
import os

directories = []

def add_directory(line):
 if line.startswith('d'):
  bits = line.split()
  dirname = bits[8]
  directories.append(dirname)

def makeDir(archiveTo):
 for dir in directories:
  newDir = os.path.join(archiveTo, dir)
  if os.path.isdir(newDir) == True:
   print("Directory \"" + dir + "\" already exists!")
  else:
   os.mkdir(newDir)

def getFiles(archiveTo, ftp):
 files = ftp.nlst()
 for filename in files:
  try:
   directories.index(filename)
  except:
   ftp.retrbinary('RETR %s' % filename, open(os.path.join(archiveTo, filename), 'wb').write)

def runBackups():

 #Load INI
 filename = 'connections.ini'
 config = configparser.SafeConfigParser()
 config.read(filename)

 connections = config.sections()
 i = 0

 while i < len(connections):
  #Load Settings
  uri = config.get(connections[i], "uri")
  username = config.get(connections[i], "username")
  password = config.get(connections[i], "password")
  backupPath = config.get(connections[i], "backuppath")
  archiveTo = config.get(connections[i], "archiveto")

  #Start Back-ups
  ftp = ftplib.FTP(uri)
  ftp.login(username, password)
  ftp.cwd(backupPath)

  #Map Directory Tree
  ftp.retrlines('LIST', add_directory)

  #Make Directories Locally
  makeDir(archiveTo)

  #Gather Files
  getFiles(archiveTo, ftp)

  #End connection and increase counter.
  ftp.quit()
  i += 1

 print()
 print("Back-ups complete.")
 print()

Answer 1

这是一种替代方案。你可以试试使用 ftputil 这个包。然后你可以用它来 浏览远程目录，这样就能获取你的文件了。

Answer 2

这是一个很早的问题，不过我有类似的需求，想用一种比较通用的方式来解决。最后我写了自己的解决方案，效果很好。我把它放在了Gist上，链接在这里 https://gist.github.com/Jwely/ad8eb800bacef9e34dd775f9b3aad987

我也把代码粘贴在下面，以防我以后把Gist下线。

使用示例：

import ftplib
ftp = ftplib.FTP(mysite, username, password)
download_ftp_tree(ftp, remote_dir, local_dir)

上面的代码会在ftp主机上查找一个叫“remote_dir”的文件夹，然后把这个文件夹及其所有内容复制到“local_dir”中。它会调用下面的脚本。

import ftplib
import os

def _is_ftp_dir(ftp_handle, name, guess_by_extension=True):
    """ simply determines if an item listed on the ftp server is a valid directory or not """

    # if the name has a "." in the fourth to last position, its probably a file extension
    # this is MUCH faster than trying to set every file to a working directory, and will work 99% of time.
    if guess_by_extension is True:
        if name[-4] == '.':
            return False

    original_cwd = ftp_handle.pwd()     # remember the current working directory
    try:
        ftp_handle.cwd(name)            # try to set directory to new name
        ftp_handle.cwd(original_cwd)    # set it back to what it was
        return True
    except:
        return False


def _make_parent_dir(fpath):
    """ ensures the parent directory of a filepath exists """
    dirname = os.path.dirname(fpath)
    while not os.path.exists(dirname):
        try:
            os.mkdir(dirname)
            print("created {0}".format(dirname))
        except:
            _make_parent_dir(dirname)


def _download_ftp_file(ftp_handle, name, dest, overwrite):
    """ downloads a single file from an ftp server """
    _make_parent_dir(dest)
    if not os.path.exists(dest) or overwrite is True:
        with open(dest, 'wb') as f:
            ftp_handle.retrbinary("RETR {0}".format(name), f.write)
        print("downloaded: {0}".format(dest))
    else:
        print("already exists: {0}".format(dest))


def _mirror_ftp_dir(ftp_handle, name, overwrite, guess_by_extension):
    """ replicates a directory on an ftp server recursively """
    for item in ftp_handle.nlst(name):
        if _is_ftp_dir(ftp_handle, item):
            _mirror_ftp_dir(ftp_handle, item, overwrite, guess_by_extension)
        else:
            _download_ftp_file(ftp_handle, item, item, overwrite)


def download_ftp_tree(ftp_handle, path, destination, overwrite=False, guess_by_extension=True):
    """
    Downloads an entire directory tree from an ftp server to the local destination

    :param ftp_handle: an authenticated ftplib.FTP instance
    :param path: the folder on the ftp server to download
    :param destination: the local directory to store the copied folder
    :param overwrite: set to True to force re-download of all files, even if they appear to exist already
    :param guess_by_extension: It takes a while to explicitly check if every item is a directory or a file.
        if this flag is set to True, it will assume any file ending with a three character extension ".???" is
        a file and not a directory. Set to False if some folders may have a "." in their names -4th position.
    """
    os.chdir(destination)
    _mirror_ftp_dir(ftp_handle, path, overwrite, guess_by_extension)

Answer 3

这段代码应该能解决问题 :)

import sys
import ftplib
import os
from ftplib import FTP
ftp=FTP("ftp address")
ftp.login("user","password")

def downloadFiles(path,destination):
#path & destination are str of the form "/dir/folder/something/"
#path should be the abs path to the root FOLDER of the file tree to download
    try:
        ftp.cwd(path)
        #clone path to destination
        os.chdir(destination)
        os.mkdir(destination[0:len(destination)-1]+path)
        print destination[0:len(destination)-1]+path+" built"
    except OSError:
        #folder already exists at destination
        pass
    except ftplib.error_perm:
        #invalid entry (ensure input form: "/dir/folder/something/")
        print "error: could not change to "+path
        sys.exit("ending session")

    #list children:
    filelist=ftp.nlst()
    
    for file in filelist:
        try:
            #this will check if file is folder:
            ftp.cwd(path+file+"/")
            #if so, explore it:
            downloadFiles(path+file+"/",destination)
        except ftplib.error_perm:
            #not a folder with accessible content
            #download & return
            os.chdir(destination[0:len(destination)-1]+path)
            #possibly need a permission exception catch:
            with open(os.path.join(destination,file),"wb") as f:
                ftp.retrbinary("RETR "+file, f.write)
            print file + " downloaded"
    return

source="/ftproot/folder_i_want/"
dest="/systemroot/where_i_want_it/"
downloadFiles(source,dest)