Interpreting Left to right?

[Tycho Andersen]

On Fri, Jun 24, 2011 at 12:14:27AM -0700, Ethan Furman wrote:
 
> The example given to me when I had this question:
> 
> --> x = x['huh'] = {}
> --> x
> {'huh': {...}}
> 
> 
> As you can see, the creation of the dictionary is evaluated, and
> bound to the name 'x'; then the key 'huh' is set to the same
> dictionary.

Can you please elaborate? I really don't understand how this works at
all. I would have expected a NameError from this (obviously my mental
model is wrong).

This single line is equivalent to:

x = {}
x['huh'] = x

...but I don't understand how python's evaluation semantics get from
the one liner to the two liner/result at all.

\t