code: def _get_module_filename(module):
      
      # Split up the module and its containing package, if it has one
      module = module.split('.')
      package = '.'.join(module[:-1])
      module = module[-1]
  
      try:
          if not package:
              # We aren't accessing a module within a package, but rather a top
              # level package, so it's a straight up import
              module = __import__(module)
          else:
              # Import the package containing our desired module
              package = __import__(package, fromlist=[module])
              # Get the module from that package
              module = getattr(package, module, None)
  
          filename = getattr(module, '__file__', None)
          if not filename:
              # No filename? Nothing to do here
              return Unparseable()
  
          # If we get a .pyc, strip the c to get .py so we can parse the source
          if filename.endswith('.pyc'):
              filename = filename[:-1]
              if not os.path.exists(filename) and os.path.isfile(filename):
                  # If there's only a .pyc and no .py it's a compile package or
                  # egg and we can't get at the source for parsing
                  return Unparseable()
          # If we have a package, we want the directory not the init file
          if filename.endswith('__init__.py'):
              filename = filename[:-11]
  
          # Yey, we found it
          return filename
      except ImportError:
          # Definitely not a valid module or package
          return
docs: Return the filename of `module` if it can be imported.
  
      If `module` is a package, its directory will be returned.
  
      If it cannot be imported ``None`` is returned.
  
      If the ``__file__`` attribute is missing, or the module or package is a
      compiled egg, then an :class:`Unparseable` instance is returned, since the
      source can't be retrieved.
  
      :param module: A module name, such as ``'test.test_config'``
      :type module: str