What does Error: 'module' object is not callable Mean?

[Cal Who]

The below code produces the error as indicated. But, in
 E:\Python26\Lib\site-packages\ffnet\tools I see:
    drawffnet.py
    drawffnet.pyc
    drawffnet.pyo
Is that what it is looking for?

I'm not sure what "not callable" means.
Could it be referencing to "nn" rather than drawffnet?
What should I do to investigate this?

Thanks
from ffnet import ffnet, mlgraph, readdata

...snipped working code here ...

output, regression = nn.test(inputs2, targets2, iprint = 2)

from ffnet.tools import drawffnet
import pylab
drawffnet(nn)   #Error: 'module' object is not callable
pylab.show()
except ImportError, e:
print "Cannot make drawffnet plot."