Alan Bromborsky wrote:
> I wish to create a list of empty lists and then put something in one of
> the empty lists. Below is what I tried, but instead of appending 1 to
> a[2] it was appended to all the sub-lists in a. What am I doing wrong?
>
> a = 6*[[]]
> >>> a
> [[], [], [], [], [], []]
> >>> a[2].append(1)
> >>> a
> [[1], [1], [1], [1], [1], [1]]
> >>>
What you've done is equivalent to
x = []
a = [x, x, x, x, x, x]
del x
An idiom for what you want is
a = [[] for y in xrange (6)]
which will populate a with 6 distinct empty lists.
Cheers, Mel.
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