Python ftp下载和存档

Question

I have been trying to script a code with python to grade the main directory of that ftp and archive it into a the local pc. I am not an amateur coder and python is fairly new to me. What I am getting as an error right now is.

File "C:\Users\Ali\Desktop\ftp_archiving_script.py", line 24, in <module>
ftpDownload = ftp.retrbinary('RETR', filename)

Code:

    from ftplib import FTP
import zipfile
import os
try:
    import zlib
    compression = zipfile.ZIP_DEFLATED
except:
    compression = zipfile.ZIP_STORED
modes = { zipfile.ZIP_DEFLATED: "deflated",
          zipfile.ZIP_STORED: "stored",
    }

#print "Logging in..."
with FTP('xxx.xxx.xxx') as ftp: #hostname goes here
    ftp.login('xxxx','xxxx') #user followed by pass
    #print "changing to root directory"
    ftp.mlsd('//')
    #print "Accessing files"
    filenames = []
    #print filenames
    ftp.retrlines('NLST', filenames.append)
    try:
        for filename in filenames:
            ftpDownload = ftp.retrbinary('RETR', filename)
            with ZipFile(os.path.join('C:\\','DC_archive.zip'), 'w') as myzip:
                myzip.write(ftpDownload, compress_type=compression)
                myzip.close()
    finally:
        #print "closing"
        ftp.close()
    ftp.quit()

Can anyone enlighten me on this problem.

Thank you,

Update

try:
    for filename in filenames:
        with io.StringIO() as fObject:
            ftp.retrbinary('RETR %s' %filename, fObject.write)
            with ZipFile(os.path.join('C:\\','DC_archive.zip'), 'w') as myzip:
                myzip.write(fObject, compress_type=compression)
                myzip.close()

updated Traceback for @fals... Also this is using your code below and not the one I have at the top.

    Traceback (most recent call last):
  File "C:\Users\Ali\Desktop\ftp_archive2.py", line 20, in <module>
    ftpDownload = ftp.retrbinary('RETR ' + filename, f.write)
  File "C:\Python33\lib\ftplib.py", line 424, in retrbinary
    with self.transfercmd(cmd, rest) as conn:
  File "C:\Python33\lib\ftplib.py", line 386, in transfercmd
    return self.ntransfercmd(cmd, rest)[0]
  File "C:\Python33\lib\ftplib.py", line 352, in ntransfercmd
    resp = self.sendcmd(cmd)
  File "C:\Python33\lib\ftplib.py", line 259, in sendcmd
    return self.getresp()
  File "C:\Python33\lib\ftplib.py", line 233, in getresp
    raise error_perm(resp)
ftplib.error_perm: 550 File not found

Answer 1

From the Python documentation for ftplib.retrbinary :

FTP.retrbinary(command, callback[, maxblocksize[, rest]])

Retrieve a file in binary transfer mode. command should be an appropriate RETR command: 'RETR filename'. The callback function is called for each block of data received, with a single string argument giving the data block.

Nowhere does it indicate that it returns a file-like object or string.

Instead, you have to create your own callback to write to a file object.

with open('my-downloaded-file', 'wb') as f:
    ftp.retrbinary('RETR %s' % filename, f.write)

Here, f.write is the callback which will receive data as it arrives from the socket. If you don't want to save the file to disk using open , you can use the StringIO module to simulate a file in memory.

Answer 2

Try following code:

import ftplib
from io import BytesIO
import os
import zipfile

REMOTE_HOST = 'xxx.xxx.xxx'
REMOTE_USER = '...'
REMOTE_PASS = '...'
REMOTE_DIR_PATH = '//'
LOCAL_ZIP_PATH = os.path.join(os.path.expanduser('~'), 'Desktop', 'DC_archive.zip')

ftp = ftplib.FTP(REMOTE_HOST)
try:
    ftp.login(REMOTE_USER, REMOTE_PASS)
    ftp.cwd(REMOTE_DIR_PATH)
    filenames = ftp.nlst()
    with zipfile.ZipFile(LOCAL_ZIP_PATH, 'w') as zf:
        for filename in filenames:
            with BytesIO() as f:
                try:
                    ftpDownload = ftp.retrbinary('RETR ' + filename, f.write)
                    zf.writestr(filename, f.getvalue())
                except ftplib.Error as e:
                    print('Skip {}: {}'.format(filename, e))
finally:
    ftp.quit()