Parsing a string containing backslash to list in Python

Question

I have a string:

str = '[\'RED\', \'GREEN\', \'BLUE\']'

I want to parse it to

list = ['RED','GREEN','BLUE']

But, I am unable to do so.

I tried to parse using json.loads:

json.loads(str)

It gave me:

{JSONDecodeError}Expecting value: line 1 column 2 (char 1)

For the record, @Ch3steR's solution is safer and I do prefer that one. — dspencer, Mar 20 '20 at 08:13
@learner Becareful while using `eval`. Using `eval` on untrusted strings can be dangerous. Use `ast.literal_eval` — Ch3steR, Mar 20 '20 at 08:14
Check this blog post of Ned Batchelder [Eval really dangerous](https://nedbatchelder.com/blog/201206/eval_really_is_dangerous.html) — Ch3steR, Mar 20 '20 at 08:16
@Ch3steR I have removed my answer and upvoted yours so that we can promote safer practices. — dspencer, Mar 20 '20 at 08:16
You might want look at this @learner [eval vs ast.literal_eval](https://stackoverflow.com/questions/15197673/using-pythons-eval-vs-ast-literal-eval) — Ch3steR, Mar 20 '20 at 08:22

score 5 · Accepted Answer · edited Mar 20 '20 at 08:21

5

You can use ast.literal_eval. eval can be dangerous on untrusted strings. You ast.literal_eval which evaluates only valid python structures.

import ast
s = '[\'RED\', \'GREEN\', \'BLUE\']'
ast.literal_eval(s)
# ['RED', 'GREEN', 'BLUE']

edited Mar 20 '20 at 08:21

dspencer

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answered Mar 20 '20 at 08:11

Ch3steR

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score 0 · Answer 2 · answered Mar 20 '20 at 08:45

0

You can use python's in-built function eval(). This works for conversion to python's other default data structures(dict, tuples, etc) as well. Something like:

str = '[\'RED\', \'GREEN\', \'BLUE\']'
l = eval(str)

answered Mar 20 '20 at 08:45

windstorm

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Parsing a string containing backslash to list in Python

2 Answers2