why cannot assign to function call

[Terry Reedy]

Aaron Brady wrote:

> 
> Containers are funny in Python in that 'a in a' can be true. 
> It can't in real containers.

Guido uses 'container' in the Ref Manual because such 'contain' 
references (of an undefined nature).  Thinking more abstractly, I use 
'collection', rather that 'container' and think of the object as a 
'roster' -- like for the members of a club.  A bibliography of 
bibliographies could list itself but would only metaphorically 'contain' 
itself.  An association of associations could conceivably be a member of 
itself.

tjr