The module tarfile contains some methods for knowing whether an archive member is a regular file/a directory/a symlink. Apart from an "is_dir()" method, there was nothing alike in the zipfile module. For an on-going project, I needed to know whether an archive member was a symlink or not, to prevent zip symlinks attacks.

I thought this could be of used for other people, given I struggled a little to find a way of saying if an archive member is a symlink or not.

This is why I think adding support for symlinks in the zipfile module could be a good idea.

The PR went through review and has been awaiting core review for almost a month, anyone to have a look at it? :)

If I understand correctly, 
this bug is about supporting symlinks on *creating* ZIP files.

Please see also https://bugs.python.org/issue27318 for a proposal to support symlinks while *unpacking* ZIP files.

Maybe a preserve_symlinks optional argument should be added to the `extract` and `extractall` method as well (the same argument name is used in `distutils.dir_util.copy_tree`).

Anyway, I think symlink support should be added for packing *and* unpacking or not at all.

Adding support of symlinks in ZIP files will make the zipfile module vulnerable to symlink attacks like like with TAR files (see https://en.wikipedia.org/wiki/Tar_(computing)#Duplicates). Until we find a solution to this, adding support of symlinks is dangerous.