How do I simply transfer and download a file from an FTP server with Python?

I've noticed that the FTP library doesn't seem to have a method or function of straight up downloading a file from an FTP server. The only function I've come across for downloading a file is ftp.retrbinary and in order to transfer the file contents, you essentially have to write the contents to a pre-existing file on the local computer where the Python script is located.

Is there a way to download the file as-is without having to create a local file first?

Edit: I think the better question to ask is: do I need to have a pre-existing file in order to download an FTP server file's contents?