“Map” a nested list in Python

Question

In Python, I am trying to apply an operator to a two layer nested array. For example,

a = [[\'2.3\',\'.2\'],[\'-6.3\',\'0.9\']]
for j in range(2)
    for i in r         


        

Answer 1

Under the hood, map is a loop too. You should just use a list comprehension, however there is a nice way to do it with Python2 - you just need a partial function

>>> a = [['2.3','.2'],['-6.3','0.9']]
>>> from functools import partial
>>> map(partial(map, float), a)
[[2.3, 0.2], [-6.3, 0.9]]

I don't think there is a nice way to convert this to Python3 though

>>> list(map(list, map(partial(map, float), a)))  #YUKKK!
[[2.3, 0.2], [-6.3, 0.9]]