Initializing a list with copies

Ralf Juengling juenglin at informatik.uni-freiburg.de
Fri Apr 26 04:57:10 EDT 2002


Hi,

does anybody see an easy way to do the following:
I need a list of initially empty lists that are to be
filled, l say. The parameter n says how many empty
lists l should contain. Someone tried 

>>> l = [[]]*n

to create l. However, this is not what he wanted:
>>> n
2
>>> l
[[], []]
>>> l[0].append(1)
>>> l
[[1], [1]]


To create an l with inidividual empty lists, he now
does
>>> l = [[] for i in range(n)]


Can this be done more elegant? By some expression that 
was similar to '[[]]*n' ?

Thanks,
Ralf



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