Lazy module variables–can it be done?

You can’t do it with modules, but you can disguise a class “as if” it was a module, e.g., in itun.py, code…:

import sys

class _Sneaky(object):
  def __init__(self):
    self.download = None

  @property
  def DOWNLOAD_PATH(self):
    if not self.download:
      self.download = heavyComputations()
    return self.download

  def __getattr__(self, name):
    return globals()[name]

# other parts of itun that you WANT to code in
# module-ish ways

sys.modules[__name__] = _Sneaky()

Now anybody can import itun… and get in fact your itun._Sneaky() instance. The __getattr__ is there to let you access anything else in itun.py that may be more convenient for you to code as a top-level module object, than inside _Sneaky!_)