Simple list.append() question

Quinn Dunkan quinn at photo.ugcs.caltech.edu
Mon Apr 24 19:48:10 CEST 2000


On Mon, 24 Apr 2000 11:19:24 -0400, Matthew Hirsch <meh9 at cornell.edu> wrote:
>Hi All,
>
>I have this:
>>>> entire_list=[[]]*3
>>>> entire_list
>[[], [], []]
>>>> entire_list[0].append(1.23)
>>>> entire_list
>[[1.23], [1.23], [1.23]]
>
>I only want to append 1.23 to entire_list[0].  Why did it also append it 
>to entire_list[1] and entire_list[2]?

When you multiply a list, you get multiple references to the *same* object.
See FAQ 4.50




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