Concise idiom to initialize dictionaries

[Brian Quinlan]

Frohnhofer, James wrote:
> My initial problem was to initialize a bunch of dictionaries at the start of a
> function.
> 
> I did not want to do
> def fn():
> 	a = {}
> 	b = {}
> 	c = {}
> 	. . .
> 	z = {}
> simply because it was ugly and wasted screen space.
> 
> First I tried:
> 
> 	for x in (a,b,c,d,e,f,g): x = {}
> 
> which didn't work (but frankly I didn't really expect it to.)
> Then I tried:
> 
> 	for x in ('a','b','c','d','e','f','g'): locals()[x]={}
> 
> which did what I wanted, in the interpreter.  When I put it inside a function,
> it doesn't seem to work.  If I print locals() from inside the function, I can
> see them, and they appear to be fine, but the first time I try to access one
> of them I get a "NameError: global name 'a' is not defined"
> 
> Now obviously I could easily avoid this problem by just initializing each
> dictionary, but is there something wrong about my understanding of locals,
> that my function isn't behaving the way I expect?

The locals dictionary should be considered read-only. Wouldn't having a 
list of dictionaries be a better strategy?

Cheers,
Brian