Generating a random subsequence

Tom Bryan tbryan at
Wed Jan 9 05:30:42 CET 2002

Alex Martelli wrote:

> can become:
>           templist = list(seq)
>           random.shuffle(templist)
>           for item in templist[:length]:
>               returnSeq += item
> The += augmented operator dispatches appropriately to in-place or
> not-in-place mutation depending on LHO's mutable/immutable nature.

Is that just true of +=? 

That is, if returnSeq is a list then, I can say
returnSeq = returnSeq + item
returnSeq.append( item )
returnSeq += item

You're saying that the last one is roughly equivalent to the second one and 
not the first?  Or are they all three equivalent?


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