How do I preserve file date and time with ftp and python?

I'm copying some files from an ftp site, to a local site, using a python script. But the default behavior has the local file with the current date-time, rather than the original date-time.

I'm getting all the files matching "abc*.csv", and copying them to a local temp directory. It works fine, but the file date-time of the original files are not getting preserved.

Any ideas:

Here's my script

#!/usr/bin/python
import ftplib
ftp = ftplib.FTP('..')
ftp.login('..')
data = []
ftp.dir('abc*.csv',data.append)
for f in data:
        y=ftp.retrbinary("RETR %s" % fname, open('tmp1/%s' % fname,"wb").write)