How to get list as an input from command line python?

Question

I know that we can use sys.argv, but I am having an issue with this.

I want to pass a list as an argument :

Example [5,1,6,[5,2]]

This is a nested list and I want to take it as input the way it is.

python myprogram.py [5,1,6,[5,2]]

This is my program:

import sys;


input_list = sys.argv[1].split(',')
print(input_list)

I did obtain the list, however if I output it, it is completely wrong structurally:

['[5', '1', '6', '[5', '2]]']

As you can see, instead of input_list[0] == 5 , I have it equal to '[5', also the nested list that I inputted now is no more nested. Instead of input_list[3] ==[5,2], input_list[3] is equal to '[5'.

What should I do? I need to take the list as it is in order to work with it.

You *could* `eval()` it, but I'd rather suggest you look at the `argparse` module to see if that can help you. — brunns, May 08 '19 at 11:35

score 2 · Answer 1 · answered May 08 '19 at 11:35

2

Try this:

import ast

input_list = ast.literal_eval(sys.argv[1])

then the output will be

[5, 1, 6, [5, 2]]

answered May 08 '19 at 11:35

Mehrdad Pedramfar

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Note that you have to hand the args as an explicit string like `python myprogram.py "[5, 1, 6, [5, 2]]"` – Björn Böing May 08 '19 at 11:37
@BreakBB Yes thanks – Mehrdad Pedramfar May 08 '19 at 11:38
A minimal explanation of what is going on under the scenes would be helpful to help OP progress IMHO. But that is present in the duplicate – Diane M May 08 '19 at 11:39

How to get list as an input from command line python?

1 Answers1