indices[i:] = indices[i+1:] + indices[i:i+1]
Hope someone helps.
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1not familiar with python, so am not sure what this does. Seems like it could be explained in a sentence. Then I could try to help.Peter Perháč– Peter Perháč2009-05-16 13:27:15 +00:00Commented May 16, 2009 at 13:27
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2 Answers
I'm fairly new to Python but if I understand the code correctly, it reconstructs a list from a given offset into every item following offset+1 and the item at the offset.
Running it seems to confirm this:
>>> indices = ['one','two','three','four','five','six']
>>> i = 2
>>> indices[i:] = indices[i+1:] + indices[i:i+1]
>>> indices
['one', 'two', 'four', 'five', 'six', 'three']
In Javascript can be written:
indices = indices.concat( indices.splice( i, 1 ) );
Same entire sequence would go:
>>> var indices = ['one','two','three','four','five','six'];
>>> var i = 2;
>>> indices = indices.concat( indices.splice( i, 1 ) );
>>> indices
["one", "two", "four", "five", "six", "three"]
This works because splice is destructive to the array but returns removed elements, which may then be handed to concat.
3 Comments
Borgar
Is it obvious that the last sentence is contrived just to fit in some links to the methods on MDC? :-)
Borgar
It is an imaginary command line. I ran the code with FireBug but added the >>> in the end simply to make it look the same as the Python block. :-)
Nosredna
@Borgar, I will buy your imaginary command line. How much does it cost, in Quatloos?
You will want to look at Array.slice()
var temp=indices.slice(i+1).concat(indices.slice(i, i+1));
var arr=[];
for (var j=0; j<temp.length; j++){
arr[j+i]=temp[i];
}
answered May 16, 2009 at 12:49
Leonard Ehrenfried
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