Newbie question: Allocation vs references

Steven Bethard steven.bethard at
Thu Jun 2 18:31:31 CEST 2005

Stian Søiland wrote:
> There are several ways to create a copy of a list:
> a2 = list(a)       # create a new list object out of any sequence

I'll just point out that FWIW, this is by far my favorite idiom of the 
ones offered because it applies to pretty much all the builtin container 

py> d = {1:42, -37:0}
py> d2 = dict(d)
py> d == d2, d is d2
(True, False)
py> s = set(['a', 'd', 'e'])
py> s2 = set(s)
py> s == s2, s is s2
(True, False)
py> L = [3.14, 0.707]
py> L2 = list(L)
py> L == L2, L is L2
(True, False)


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