[Python-Dev] docs - Copy

Rich Healey healey.rich at gmail.com
Fri Jun 25 03:14:39 CEST 2010


On Fri, Jun 25, 2010 at 11:04 AM, Steve Holden <steve at holdenweb.com> wrote:
> Rich Healey wrote:
>> http://docs.python.org/library/copy.html
>>
>> Just near the bottom it reads:
>>
>> """Shallow copies of dictionaries can be made using dict.copy(), and
>> of lists by assigning a slice of the entire list, for example,
>> copied_list = original_list[:]."""
>>
>>
>> Surely this is a typo? To my understanding, copied_list =
>> original_list[:] gives you a clean copy (slicing returns a new
>> object....)
>>
> Yes, but it's a shallow copy: the new object references exactly the same
> objects as the original list (not copies of those objects). A deep copy
> would need to copy any referenced lists, and so on.
>

My apologies guys, I see now.

I will see if I can think of a less ambiguous way to word this and submit a bug.

Thankyou!


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