How to extract a list from a string in a list in python

Question

I read a list of lists from a txt file and I got a list like this:

["[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793]", "[21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]"]

Each list item in this list is a str type which is a problem.

it should be like this:

[[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793], [21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]]

How do I do that?

@TheFungusAmongUs Consider changing the link you've provided to this: [Do not use signature, taglines, greetings, thanks, or other chitchat.](https://stackoverflow.com/help/behavior) because the one you've provided is irrelevant to the issue you've raised. — Jeffrey Ram, Aug 29 '22 at 02:32

Jeffrey Ram · Answer 1 · 2022-08-29T02:25:34.857

1

Consider using literal_eval:

from ast import literal_eval

txt = ["[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793]", "[21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]"]

result = [literal_eval(i) for i in txt]

print(result)

Output:

[[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793], [21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]]

Edit:

Or eval(). Refer to Tim Biegeleisen's answer.

edited Aug 29 '22 at 02:25

answered Aug 29 '22 at 02:11

Jeffrey Ram

1,132
1
10
16

score 0 · Accepted Answer · answered Aug 29 '22 at 02:12

Using the eval() function along with a list comprehension we can try:

inp = ["[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793]", "[21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]"]
output = [eval(x) for x in inp]
print(output)

This prints:

[
    [21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793],
    [21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]
]

Vae Jiang · Answer 3 · 2022-08-29T02:47:27.760

0

Here is how I will solve it.

from typing import List

def integer_converter(var: str):
    try: 
    # I used float here in case you have any float in those strs
    return float(var)
    except ValueError:
    # if ValueError, then var is a str and cannot be converted. in this case, return str var
    return var

def clear_input(raw_input: List[str]) -> List:
    raw_input = [x.replace('[','').replace(']','').replace("'",'').replace(' ','').split(',') for x in raw_input]
    raw_input = [[integer_converter(x) for x in sublist] for sublist in raw_input]
    return raw_input

test = ["[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793]", "[21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]"]
test = clear_input(test)
print(test)

edited Aug 29 '22 at 02:47

answered Aug 29 '22 at 02:22

Vae Jiang

337
3
8

This solution does not work with `["[21049090, 'AARTIIND22AUGFUT', 'AARTIIND', 850, 1793]", "[21049346, 'ABB22AUGFUT', 'ABB', 250, 3329]"]` – Jeffrey Ram Aug 29 '22 at 02:29
@JeffreyRam, you are right. I modified my answer, and it should now work for the direct read from a file. – Vae Jiang Aug 29 '22 at 02:48

How to extract a list from a string in a list in python

3 Answers3