Is there a simple way to make lists behave as files (with ftplib)

Question

I'd like to use ftplib to upload program-generated data as lists. The nearest method I can see for doing this is ftp.storlines, but this requires a file object with a readlines() method.

Obviously I could create a file, but this seems like overkill as the data isn't persistent.

Is there anything that could do this?:

session = ftp.new(...)
upload = convertListToFileObject(mylist)
session.storlines("STOR SOMETHING",upload)
session.quit

Answer 1

You could always use StringIO (documentation), it is a memory buffer that is a file-like object.

from io import StringIO    # version < 2.6: from StringIO import StringIO

buffer = StringIO()
buffer.writelines(mylist)
buffer.seek(0)

session.storlines("...", buffer)

Note that the writelines method does not add line separators. So you need to make sure that each string in mylist ends with a \n. If the items in mylist do not end with a \n, you can do:

buffer.writelines(line + '\n' for line in mylist)