Guilherme Polo wrote:
On Tue, Nov 11, 2008 at 5:47 PM, Eric <[EMAIL PROTECTED]> wrote:
I'm learning Python (while coming from MATLAB). One question I have is
that if I have a list with say 8 elements, and I want just a few of
them how do I select them out. In MATLAB, if I just want the first,
fifth and eighth element I might do something like this:

b = a([1 5 8]);

I can't seem to figure out a similar Python construct for selecting
specific indices. Any suggestions?

MATLAB works with 1-based index, while Python is 0-based, so accessing
the index number 8 wouldn't be valid with 8 elements here in Python.

Now, to solve your problem you could either use the already suggested
answer above mine or depending on what you what else you wanna do, you
will feel more comfortable using numpy.

Supposing you have a array with 8 elements: x = numpy.arange(8)
To pull out the first, fifth and eighth elements you would do:
x[numpy.array([0, 4, 7])]

Actually, x[[0,4,7]] will work just as well.

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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