What is the neatest way to multiply element-wise a list of lists of numbers?
E.g.
[[1,2,3],[2,3,4],[3,4,5]]
-> [6,24,60]
import operator
import functools
answer = [functools.reduce(operator.mul, subl) for subl in L]
Or, if you prefer map:
answer = map(functools.partial(functools.reduce, operator.mul), L) # listify as required
Use np.prod
:
>>> a = np.array([[1,2,3],[2,3,4],[3,4,5]])
>>> np.prod(a,axis=1)
array([ 6, 24, 60])
Use a list comprehension and reduce
:
>>> from operator import mul
>>> lis = [[1,2,3],[2,3,4],[3,4,5]]
>>> [reduce(mul, x) for x in lis]
[6, 24, 60]