[Tutor] is gotchas?

Tim Johnson tim at johnsons-web.com
Tue Nov 7 01:22:29 CET 2006


* Kent Johnson <kent37 at tds.net> [061106 10:31]:
> 
> In [9]: a=[1,2]
> 
> In [10]: b=[1,2]
 
  Hmmm! Hmmm!
  Lookee here:
  ## console session
>>> a=[1,2]
>>> b=[1,2]
>>> a is b
False
>>> c='1'  ## one byte
>>> d='1'  ## one byte
>>> c is d
True
>>> c='1,2'
>>> d='1,2'
>>> c is d
False

The Hmmm! is emmitted because I'm thinking that if everything is an
object in python, then why does `c is d` evaluate to True when
the assigned value is 1 byte and evaluate to False when the assigned
value is more that 1 byte?

I think I ran into this before and that's why I never used `is'.

Good thread. Beats flame wars.
thanks
tim

-- 
Tim Johnson <tim at johnsons-web.com>
      http://www.alaska-internet-solutions.com


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