two python questions about function attrib.

[sail]

python-listhello all, 
   I am  reading the "Python ref-Man" after Tutorial , this is I read it
second. the first time,  I can not understand it all, but I think I must read again in future. so Now , I reading. :), have a bit verbosity.
   I have two questions about function Special attributes:

   1. what is mean of attrib func_dict or __dict__? I defined a function
	  Afunc()  as follow:
       def Afunc():
			""" A func example"""
			print "Afunc" 

	  why Afunc.__dict__ is {} ??? I do not know.

   2. like above, I can not know the attrib func_closure. in manual ,
      this say " free variables", I did not saw it ago at all.

		who can help me? thank u.

            sail
            raise_sail at sina.com