"PEP 3108 - Standard Library Reorganization
"The Python standard library is one of the strongest libraries
around and adequately supports Python's motto of "batteries
included." But, over the years some cruft accumulated in the
standard library. Python 3.0 takes full advantage of the fact that
it's not backwardly compatible, using that lack of compatibility as
a way to "clean house." PEP 3108 describes in detail the changes to
the standard modules.
"For Python 3.0, many older modules were simply removed. These were
either already deprecated, or dropped because they weren't used
often, or because better alternatives were already available in the
standard library or in third-party packages. Many platform-specific
modules were removed too, including:
"The dl module, which has been superseded by ctypes
The dircache module, which was rarely used and easily
The ihooks module, because it was undocumented and used only by
rexec (turned off in Python 2.3 due to security issues), which has
now been removed as well.
popen2 is gone (use subprocess) as well as sets (use the builtin
set and frozenset types)
md5 and sha are gone (use hashlib)"