Subtract a value from every number in a list in Python?

Question

I have a list

 a = [49, 51, 53, 56]

How do I subtract 13 from each integer value in the list?

Answer 1

If are you working with numbers a lot, you might want to take a look at NumPy. It lets you perform all kinds of operation directly on numerical arrays. For example:

>>> import numpy
>>> array = numpy.array([49, 51, 53, 56])
>>> array - 13
array([36, 38, 40, 43])