Python Regex: Only Replace captured group

Question

I have a regex that matches an "aliases" key that is an existing list in a markdown file, and captures the closing bracket as a group.

RE_ALIASES = re.compile(r'\s*---\n.*aliases:\s?\[.*(\]|\n\]).*\n---.*', re.DOTALL)

How do I replace that captured group with my own text?

i.e.,

---
...
aliases: [
   hello,
   world
]
---
...

should be

---
...
aliases: [
   hello,
   world,
   inserted
]
---
...

In this case, the first group \n] is replaced by ,\n inserted\n]

zvone · Accepted Answer · 2019-03-28 07:21:56Z

1

I think you should use the re.sub function

Here's how it would work for your case:

(Supposing you saved your initial string as initial_string)

final_string = re.sub('(\\]|\\n\\]).*', ',\n\tinserted\n\t]', initial_string)

If you print "final_string" it shows:

---
...
aliases: [
        hello,
        world,
        inserted
        ]
---
...

zvone

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answered Mar 28, 2019 at 7:20

Lauro Bravar

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