python - How to change the string type list to a list type and then drop nan elements

Question

I have a unique problem. I am facing two issues here. First, my list is a string type, not list type. Then, some of the elements in the list are nan. I want to drop them.

My code:

x = '[1.4,2.3,nan]'
print(type(x)) # prints str
x = eval(x) # with this I want to drop end quotes, convert it to list type
print(type(x))
x = [k for k in x if str(k)!='nan'] 

Present output:

NameError: name 'nan' is not defined

Expected output:

x = [1.4,2.3]

question from:https://stackoverflow.com/questions/66052748/how-to-change-the-string-type-list-to-a-list-type-and-then-drop-nan-elements

Answer 1

Please don't use eval for anything if you're not acutely aware how unsafe it is. Instead, properly parse your input.

import math

s = '[1.4,2.3,nan]'
x = [float(n) for n in s.lstrip('[').rstrip(']').split(',')]
x = [n for n in x if not math.isnan(n)]