Question

I have a folder structure like this:

package_name/
|-- module1
|-- module2
|-- module3

What I need to do is import package_name, and then iterate over each of the modules, running code upon them one after another. The import is given at the command line, so I can’t control that ahead of time. So a user might say, run_script.py --modules='package_name.module1' or the user might simply say, run_script.py --modules='package_name.

I can do from package_name import *, and that will import everything defined in my __all__ variable in __init__.py, but from there I’m a bit stumped.

For my next step, I need a way of doing:

for module in imported:
    module.run()

Answer 1

I usually use a function like this to import a module by path:

def import_by_path(path):
  if '.' not in path:
    return __import__(path, globals(), locals())

  path, module = path.rsplit('.', 1)
  mod = __import__(path, globals(), locals(), [module])

  try:
    return getattr(mod, module)
  except AttributeError:
    raise ImportError, "Could not import %s" % path

Use like this:

mod = import_by_name("itertools")

Or in your case:

for mod in map(import_by_name, imported):
  mod.run()