namespace sharing (longish)

[Greg Ewing]

"robin"@illusionsexeculink.com.bbs at openbazaar.net wrote:
> 
> All I want to do is execute user-supplied (eg: arbitrary) functions
> and have them share a namespace.

Your example doesn't work because your one() and two() functions
live in a separate module. The global namespace of a function
defined in a module is always the namespace of that module, 
regardless of how the function gets called.

One way to do what you want is to compile() the function
definition itself:

  namespace = {'var_main': 'hello', '__builtins__': {}}
  source = """
  def one():
    global var_main
    print var_main
    var_main = 'spam'
  """
  code = compile(source, "", "exec")
  exec code in namespace # defines the function within namespace
  print namespace
  namespace["one"]()     # call the function
  print namespace

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg