How can I get an array of alternating values in python?

Question

Simple question here:

I\'m trying to get an array that alternates values (1, -1, 1, -1.....) for a given length. np.repeat just gives me (1, 1, 1, 1,-1, -1,-1, -1

Answer 1

If you want a memory efficient solution, try this:

def alternator(n):
    for i in xrange(n):
        if i % 2 == 0:
            yield 1
        else:
            yield -1

Then you can iterate over the answers like so:

for i in alternator(n):
    # do something with i