45.4. Sharing Data
  The global dictionary
  
   SD
  
  is available to store
   data between function calls.  This variable is private static data.
   The global dictionary
  
   GD
  
  is public data,
   available to all Python functions within a session.  Use with
   care.
  
  
 
  Each function gets its own execution environment in the
   Python interpreter, so that global data and function arguments from
  
   myfunc
  
  are not available to
  
   myfunc2
  
  .  The exception is the data in the
  
   GD
  
  dictionary, as mentioned above.