Pythonic way for missing dict keys

[Duncan Booth]

"Rustom Mody" <rustompmody at gmail.com> wrote:

> Can someone who knows about python internals throw some light on why
>>>> x in dic
> is cheaper than
>>>> dic.has_key(x)
> 
> ??
> 
Some special methods are optimised by having a reserved slot in the data 
structure used to implement a class. The 'in' operator uses one of these 
slots so it can bypass all the overheads of looking up an attribute such as 
'has_key'.