Invoking Unix commands from a Python app

[Rob Cowie]

Hi all,

An idea popped into my head recently for an app that would track how
much time a user spends in a particular piece of software (or at least,
for how long an application is open).

I'm assuming there is a way to do this via the command line and a unix
app, although I haven't yet invesitgated it.

My question is, can a command line application be invoked by a python
program? If so, how does one pass parameters to it and retrieve its
response?

Cheers and Merry Christmas,

Rob Cowie