socket.fromfd()'s behaviour is somewhat counter-intutive and should contain a note to warn the user that it'll leave the original FD open. This is important if someone forgets to manually close the file descriptor as it might lead to FD leaks (and kernel memory leaks). This is especially the case when there is no python object associated with the FD, so no destruction will take place.

patch applies to this:
http://docs.python.org/py3k/archives/python-3.1.2-docs-html.tar.bz2

The only thing it does is that it adds a note section with the following message: "The original file descriptor will not be closed."

synapse

Forgot to add that the changes should be applied to all versions if accepted.

synapse

I think, the original docs *is* pretty intuitive. It says "Duplicate the file descriptor fd and build a socket object".  No one will think that the this method will close the original fd. Person using this method might of course, explicitly close the original fd in some other part of the code (as he may use it after creating the socket object too).

If at all anything is required, a line may be "The original file descriptor is unaffected", but again that seems redundant to me.

You are perfectly right, the docs are pretty clear. Although fromfd means (or at least to me) to "attach object to fd" and not "duplicate then attach to the duplicate". If someone forgets this particular behaviour and thinks that the function works as the name implies they're in trouble.

Gergely Kalman

So, I assume that we just leave it as such and close the issue.
I was thinking if anything needs to be updated for function __doc__ but even there 'the duplicate' word is explained.