This python library can parse the ISO 9660 disk image format including Rock Ridge extensions. It can load ISOs from the local filesystem or via HTTP, and will only read and cache sectors as necessary. You list directory contents, extract files, and retrieve metadata.
$ pip install isoparserimport isoparser
iso = isoparser.parse("http://www.microsoft.com/linux.iso")
print iso.record("boot", "grub").children
print iso.record("boot", "grub", "grub.cfg").content