python: AttributeError, 'module' object has no attribute 'something'

Previously I asked a question here. That problem solved but there are error while developing the script.

Currently, an option is obtained from command line like:

... -b b1

the code processing that is:

import Mybench, optparse
parser.add_option("-b", "--benchmark", default="", help="The benchmark to be loaded.")  
if options.benchmark == 'b1':
   process = Mybench.b1
elif options.benchmark == 'b2':
   process = Mybench.b2
...
else:
   print "no such benchmark!"

Now I have changed so that more than one option is passed to "-b".

... -b b1,b2

The code for this is:

process = []
benchmarks = options.benchmark.split(',')
for bench_name in benchmarks:
   print bench_name
   process.append(Mybench.bench_name)

If you notice, in the first code the process gets value like this:

process = Mybench.b1

Now I write this:

process.append(Mybench.bench_name)

I expect that this command line:

... -b b1,b2

results in:

process[0] = Mybench.b1
process[1] = Mybench.b2

However I get this error:

process.append(Mybench.bench_name)
AttributeError: 'module' object has no attribute 'bench_name'

Is there any solution to that?