list in a tuple

[Wildemar Wildenburger]

Subject:   Re: list in a tuple
To:
Cc:
Bcc:
Reply-To:
Newsgroup: comp.lang.python
-=-=-=-=-=-=-=-=-=# Don't remove this line #=-=-=-=-=-=-=-=-=-
montyphyton at gmail.com wrote:
 > After some tought I must agree that this is a wart more than
 > a bug and that it will probably be best not to mess with it.
 > However, what do you guys think about the print wart in Py3k
 > described at 
http://filoxus.blogspot.com/2007/12/python-3000-how-mutable-is-immutable.html#links
 > (im not trying to advertise my blog, I just don't feel like
 > typing the whole problem all over again)?
 >

 From that post:
 > Ok, I do admit that doing
 >
 > a = ([1], 2)
 > a[0].append(2)
 >
 > also doesn't throw an error, but this only confuses me more.
 >
Why? You mutate the list, but the tuple does not change. It is still a 
tuple of a list and an int. At least that's how I think about it, and I 
seem to recall reading that beavior justified like this (don't ask me 
where though (might have been "Dive Into Python", but maybe not)).

/W