[Python-Dev] Complexity documentation request

[Dimitrios Apostolou]

Correcting myself:

Dimitrios Apostolou wrote:
> Hi,
> 
> I just dug into the source code looking for complexity of set 
> operations. In the wiki page I documented an interesting finding, that 
> it is different to do s-t and s.difference(t). It is also interesting 

it is different to do s-t than s.difference_update(t), as fas as 
complexity is involved. The first one is O(len(s)) while the second is 
O(len(t)) (I *think so, I may have missed lots of things in the source 
code).

> that you can do the first only for sets, but the second for every 
> iterable in t.
> 
> Are these portable characteristics of the python language or just 
> implementation specific details? In addition, can someone explain me the 

I just found it documented in the library reference, that s.method() can 
accept any iterable while s-t can't. So I guess it is a language 
characteristic.

> usefulness of the loop starting with 'if (PyDict_CheckExact(other))' in 
> set_difference()? As I understand it set_difference() is always called 
> with two sets as arguments (set_sub() does the actual call).
> 
> I'm just trying to figure out the complexity of the other set 
> operations, but things get more complicated. I'd appreciate your help.
> 
> 
> Thanks,
> Dimitris


P.S. Who is the wiki admin? I'm desperately trying to improve the looks 
of tables (Add border, remove the <p> element from every cell) but I 
can't. I think that the page stylesheet needs to be modified, for 
starters...