Python ftplib can't get size of file before download?

Question

I'm using ftplib to transfer files. Everything is working great. Now I'm trying to get the size of the target file before downloading.

1. First, I tried just getting size with ftp.size(filename). Server complained that I can't do that in ascii mode.

2. Then I tried setting binary mode using ftp.sendcmd("binary") and ftp.sendcmd("bin"). In both cases the server complained "500 binary Not understood"

Can ftplib get size of a file before downloading in this instance? I don't control the FTP server and can't change how it's behaving.

Thanks

Answer 1

Very late reply, but here's the correct answer. This works with ProFTPD.

ftp.sendcmd("TYPE i")    # Switch to Binary mode
ftp.size("/some/file")   # Get size of file

Answer 2

Ftplib can get the size of a file before downloading. As the documentation says:

FTP.size(filename) Request the size of the file named filename on the server. On success, the size of the file is returned as an integer, otherwise None is returned. Note that the SIZE command is not standardized, but is upported by many common server implementations

Apparently your server doesn't support this feature.