“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

With list comprehension:

a =  [[float(j) for j in i]  for i in a]