Question about references/copies
ajsiegel at optonline.com
Sat Aug 28 14:37:10 CEST 2004
On Sat, 28 Aug 2004 11:32:39 +0200, aleaxit at yahoo.com (Alex Martelli)
>Henning Kage <c0dec at gmx.de> wrote:
>> I'm using Python only for some months now and I'm wondering, whether such
>> assignments as above
>"As above" _where_?
>> are creating bitwise copies of an object or just
>> recieve a reference. That means I wanted to know, wheter Python in general
>> differs between references and copies:
>> class someclass:
>> def __init__( self, otherobject):
>> self.someattribute = otherobject
>Python makes no copy unless you explicitly ask for a copy -- what you
>get is always a reference. There are several ways to ask for copies --
>the most general and powerful ones you'll find in standard library
>modules copy (both copy.copy and copy.deepcopy -- all other ways of
>asking for a copy, except copy.deepcopy, get shallow copies).
I've felt strongly that this key piece of Python learning would be
and much, much more inevitable if there was a (preferred) consistent
way to ask for a copy, across objects - and/or that the copy module
was something other than one of XXX importable moudles.
That dicts and lists (for example) have totally different syntax for
copy, helps - I promise - to misdirect and confuse. I happen to
consider this entire area a significant wart. I think I am entitled to
consider it so.
I had tried to bring this up to in various forums, most particularly
edu-sig - where I thought this knid of discussion might be of
particular significance - and was rather rudely asked by Guido to take
it elsewhere. Where? not clear.
Ray Hettinger asked Gudio for permission to at least put a few words
about the copy module in the tutorial section mentioning a few of the
key importable modules - to at least, I think,. give new users a clue
that there was something of conceptual significance in all this. And
My only participation on python-dev was to ask Gudio to reconsider
And was - rudely - dismissed.
I promise Brett C. and Anthony B. that there is more of a 2-way
street than they might think. For some of us trying to make our own
kind of contribution in our own kind of way.
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