Invert negative values in a list

Question

I am trying to convert a list that contains negative values, to a list of non-negative values; inverting the negative ones. I have tried abs but it didn\'t work

Answer 1

The simple pythonic way is the list comprehension above but if you're using Numpy for anything else you could do:

x2 = numpy.abs(x)

with no need to convert or do any looping.