Sum one number to every element in a list (or array) in Python

python list sum
Leon palafox picture Leon palafox · Apr 22, 2011 · Viewed 108.4k times · Source

Here I go with my basic questions again, but please bear with me.

In Matlab, is fairly simple to add a number to elements in a list:

a = [1,1,1,1,1]
b = a + 1

b then is [2,2,2,2,2]

In python this doesn't seem to work, at least on a list.

Is there a simple fast way to add up a single number to the entire list.

Thanks

Answer

joaquin picture joaquin · Apr 22, 2011

if you want to operate with list of numbers it is better to use NumPy arrays:

import numpy
a = [1, 1, 1 ,1, 1]
ar = numpy.array(a)
print ar + 2

gives

[3, 3, 3, 3, 3]

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