best way to compare contents of 2 lists?

Hans DushanthaKumar hans.dushanthakumar at
Fri Apr 24 03:37:09 CEST 2009

'set' comes to mind, though I'm not sure if there are performance
inplications with large amopunts of data.

>>> a=[1, 2, 3]
>>> b=[2, 3, 1]
>>> set(a) == set(b)


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Subject: best way to compare contents of 2 lists?

What is the best way to compare the *contents* of two different
lists regardless of their respective order? The lists will have
the same number of items, and be of the same type.

E.g. a trivial example (my lists will be larger),

a=[1, 2, 3]

b=[2, 3, 1]

should yield true if a==b

I suppose I could sort them and then compare them. I.e.,


I am wondering if there is a more efficient/preferred way to do so.



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