Ping Implementation in Python

[Mrown]

Hi,
  I was wondering if there was a ping implementation written in
Python.  I'd rather using a Python module that implements ping in a
platform/OS-independent way than rely on the underlying OS, especially
as every OS has a different implementation.  Furthermore, if you're
going to ping a large number of IPs, using a module would probably be
a lot faster.  Any ideas if such a module exists?  Thanks.