Getting doc string of a python file

Question

Is there a way of getting the doc string of a python file if I have only the name of the file ? For instance I have a python file named a.py. I know that it has a doc string ( being mandated before) but don't know of its internal structure i.e if it has any classes or a main etc ? I hope I not forgetting something pretty obvious If I know it has a main function I can do it this way that is using import

     filename = 'a.py'
     foo = __import__(filename)
     filedescription = inspect.getdoc(foo.main())

I can't just do it this way:

     filename.__doc__    #it does not work

Answer 1

You should be doing...

foo = __import__('a')
mydocstring = foo.__doc__

or yet simpler...

import a
mydocstring = a.__doc__