converting string to integer in nested list - python

Question

I am a fresher to python.

I am trying to get [[7, 1], [8], [4, 0, 5]] this as result but I am keep getting [['7, 1'], ['8'], ['4, 0, 5']] .

def nested_list(f):
    opener = open(f,"r")
    lst =[lin.strip().split(" , ") for lin in opener]
    return lst

How can I correct my code?

Answer 1

You need to cast it into an int from string . One way to do it is using map

def nested_list(f):
    opener = open(f,"r")
    lst = [map(int, lin.strip().split(" , ")) for lin in opener]
    return lst

Answer 2

If your question accurately represents the file, it looks like the following, with one space after the comma:

7, 1
8
4, 0, 5

Use this:

def nested_list(f):
    with open(f) as opener:  # so the file is closed automatically.
        return [[int(x) for x in lin.strip().split(', ')] for lin in opener]

Answer 3

In place of int you can use eval function in both above answer.Int function give error when your string contain special char while eval work smoothly