How to change string into list

Question

Hi I want change a string into an list like:

'[KEYTYPE.FWPROD2KEY, KEYTYPE.FWPROD2KEY, DOWNLOADMODE.FWTOFW, False, DEPLOYMODE.DEPLOY]'

into

[KEYTYPE.FWPROD2KEY, KEYTYPE.FWPROD2KEY, DOWNLOADMODE.FWTOFW, False, DEPLOYMODE.DEPLOY]

Is `KEYTYPE.FWPROD2KEY` supposed to be a string? Some constant looked up elsewhere? The end result you're describing isn't a legal `list` literal, so you need to be more clear here. A complete [MCVE] would be ideal (not only making it clear what you want, but showing some effort). — ShadowRanger, Jan 17 '19 at 01:13
If security is not an issue, you can just do eval(list_string) - eval evaluates a string as code. — Arya, Jan 17 '19 at 01:13
`eval` evaluates a string as python, but be very careful regarding the source of your strings as it can be a security issue. — Mike Robins, Jan 17 '19 at 01:14
If security is not an issue, you can just do eval(list_string) - eval evaluates a string as code. — Arya, Jan 17 '19 at 01:14
eval will only work here if KEYTYPE.FWPROD2KEY is some kind of defined value, and not a string. — Arya, Jan 17 '19 at 01:21

score 0 · Answer 1 · answered Jan 17 '19 at 01:36

0

Here’s a simple function to deal with this, using split and replace:

Assuming that ‘stringlist’ is your string’d list...

def transformlist(stringlist):
    stringlist = stringlist.split(sep=',')
    stringlist[0] = stringlist[0].replace('[','')
    stringlist[-1] = stringlist[-1].replace(']','')
    return stringlist

answered Jan 17 '19 at 01:36

Marcelo Tournier

49
3

This evaluates to strings not variables – Jab Jan 17 '19 at 01:39

Jab · Answer 2 · 2019-01-17T02:07:10.290

You could use .split() then getattr() and ast.literal_eval()

import ast

s = '[KEYTYPE.FWPROD2KEY, KEYTYPE.FWPROD2KEY, DOWNLOADMODE.FWTOFW, False, DEPLOYMODE.DEPLOY]'

def get_val(value):
    values = value.split('.')
    if values[0] in locals: return getattr(getattr(locals, value), values[1])
    if values[0] in globals: return getattr(getattr(globals, value), values[1])
    try: return ast.literal_eval(value)
    except: return value

#slice the string to get rid of the brackets
#and .replace to remove all spaces
data = [get_val(val) for val in s[1:-1].replace(' ', '').split(',')]

This is probably the safe way of doing this.

davedwards · Answer 3 · 2019-01-17T02:23:26.400

Probably the most succinct way is use the re module to split and remove symbols from the string, then recombine the strings back into a list data structure:

import re

s = '[KEYTYPE.FWPROD2KEY, KEYTYPE.FWPROD2KEY, DOWNLOADMODE.FWTOFW, False, DEPLOYMODE.DEPLOY]'

l_str = ''.join(re.split(', [ ]', s))
l = eval(l_str)

or a one-liner:

l = eval(''.join(re.split(', [ ]', s)))

To Arya's points in the comment since I don't have those variables defined I can't test it, but you should then be able to verify the result is of type list:

>>> print(type(l))
<type 'list'>

How to change string into list

3 Answers3