__brace__ (PEP?)

[James Stroud]

Hello All,

If "__call__" allows anobject() and "__getitem__" allows anobject[arange], why 
not have "__brace__" (or some other, better name) for anobject{something}. 
Such braces might be useful for cross-sectioning nested data structures:

anary = [[1,2,3],[4,5,6]]

anary{2}  ==> [3,6]


or for a list of dictionaries:

alod = [{"bob":1,"ted":2,"carol":3},{"bob":4,"ted":5,"carol":6}]

alod{"ted"} ==> [2,5]


or, heck, a dictionary of lists:

adol = {"bob":[1,2,3],"carol":[4,5,6],"alice":[7,8,9]}

adol{1}  ==> {"bob":2, "carol":5, "alice":8}


Though I positively can not see what is wrong with this suggestion, I am sure 
this will raise more than a few objections. Please bash my naivete publicly 
on the list.

Some preemptive observations

1. on syntactic ambiguity (i.e. "braces already used")

  [] ==> used for both list and getitem (both for dict AND list)
  () ==> used for tuple, callable, grouping

2. on functional ambiguity (i.e. "function not implicit"):

  Q. What exactly does it mean to call an instance of class MyClass?
  A. Whatever the author of MyClass wanted it to mean.

etc.

Also, if this exists already, I apologize because I have not seen it in any 
Python code before and I wouldn't know what to call it for googling.

James


-- 
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095

http://www.jamesstroud.com/