Convert seconds to hours/minutes/seconds and pretty print
There is a built-in timeit module which is quite convenient for measuring execution times, but, if we were to improve this particular solution, I would switch to using divmod as suggested by Brandon here, utilize short if/else version for the status definition and join the time value parts with a comma filtering non-zero values only.

Something along these lines:

seconds = int(seconds)
status = 'has been running for' if not finished else 'finished in'

minutes, seconds = divmod(seconds, 60)
hours, minutes = divmod(minutes, 60)

periods = [('hours', hours), ('minutes', minutes), ('seconds', seconds)]
time_string = ', '.join('{} {}'.format(value, name)
                        for name, value in periods
                        if value)

print('The script {} {}'.format(status, time_string))