empty classes as c structs?

[Leif K-Brooks]

Alan McIntyre wrote:
> You could do something like this:
> 
> blah = type('Struct', (), {})()
> blah.some_field = x
> 
> I think I'd only do this if I needed to construct objects at runtime 
> based on information that I don't have at compile time, since the two 
> lines of code for your empty class would probably be more recognizable 
> to more people.

Actually, in Python, class definitions are runtime executable statements 
just like any other. You can do this:

 >>> def make_class(with_spam=True):
...  if with_spam:
...   class TheClass(object):
...    def dostuff(self):
...     print 'Spam, spam, spam, spam!'
...  else:
...   class TheClass(object):
...    def dostuff(self):
...     print "I don't like spam!"
...  return TheClass
...
 >>> make_class(True)().dostuff()
Spam, spam, spam, spam!
 >>> make_class(False)().dostuff()
I don't like spam!

And this:

 >>> class Foo(object):
...  num = 3
...  for _ in xrange(14):
...   num *= 1.22
...
 >>> Foo.num
48.546607267977542