This python library can parse the ISO 9660 disk image format including Rock Ridge and Joliet extensions. It can load ISOs and BINs (MODE1/2352) 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 isoparser
import isoparser
iso = isoparser.parse("http://www.microsoft.com/linux.iso")
print iso.record("boot", "grub").children
print iso.record("boot", "grub", "grub.cfg").content