title: Can I use __init__.py to define global variables?
body: <p>I want to define a constant that should be available in all of the submodules of a package. I've thought that the best place would be in in the <code>__init__.py</code> file of the root package. But I don't know how to do this. Suppose I have a few subpackages and each with several modules. How can I access that variable from these modules?</p>
  
  <p>Of course, if this is totally wrong, and there is a better alternative, I'd like to know it.</p>