How to split string to my favorite form in python？

Question

I have a string which is converted from a list like this：

"['station38', 'station28', 'station27', 'station1', 'station0']"

I want to split it by comma and become this：

list_str=['station38', 'station28', 'station27', 'station1', 'station0']

However I can only get this:

>>> line_stations = upstream_str.replace('[', '').replace(']', '').split(',')
["'station38'", "'station28'", "'station27'", "'station1'", "'station0'"]

And I have used strip('"'), however it failed.

So how to get my favorite form? Thank for your reply.

@DanielHao Use of `eval()` is discouraged as it poses security risks with little upside. See [here](https://stackoverflow.com/a/15197698). — stelioslogothetis, Aug 04 '22 at 13:38
@stelioslogothetis Thanks for the reminder. I knew it - just throw out as an idea... Prob. should give a *Warning* first. — Daniel Hao, Aug 04 '22 at 13:39
@DanielHao Of course, just mentioning it because newer Python users might see it and use it unaware of the risks — stelioslogothetis, Aug 04 '22 at 13:42

score 1 · Answer 1 · answered Aug 04 '22 at 13:33

You might be better off using a ready-made solution, in this case ast.literal_eval.

>>> from ast import literal_eval
>>> literal_eval("['station38', 'station28', 'station27', 'station1', 'station0']")
['station38', 'station28', 'station27', 'station1', 'station0']

That is because there could be all kinds of cases that an ad-hoc solution probably doesn't cover, e.g., something like "station42'".

stelioslogothetis · Accepted Answer · 2022-08-04T13:41:25.867

1

You're almost there! The quote you want to get rid of isn't ", but '. You can use replace as before:

upstream_str.replace('[', '').replace(']', '').replace("'", "").split(',')

strip() removes a matching character that is at either end of the string. In your case that doesn't work, because before doing split(",") the string is:

"'station38', 'station28', 'station27', 'station1', 'station0'"

Notice that the ' are all over the middle of the string before you split it into a list. strip is useful however, for removing the []:

upstream_str.strip('[]').replace("'", "").split(',')

You can also look at evaluating the string directly to recover the original list in one operation. I advise looking at the StackOverflow thread on literal_eval.

edited Aug 04 '22 at 13:41

answered Aug 04 '22 at 13:34

stelioslogothetis

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You could replace the `.replace('[', '').replace(']', '')` with `.strip('[]')`. – isaactfa Aug 04 '22 at 13:38
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@isaactfa Thanks! Didn't realise – stelioslogothetis Aug 04 '22 at 13:42

How to split string to my favorite form in python？

2 Answers2