How to remove square brackets in a column?

Try text to replace

\[(.*)\]

Replacement text

\1

You could also use a string pair replacer, with the following replacement pairs

[ "" ] ""

\[(.*)\]

\1

@david_r   thank you very much for the formulation of the regular expression,

however I have another issue. It appeared afterwards that the comma in the [Park5, Park4]"  for example led to some problems when importing into another software, therefore, the comma preferably should also be deleted. I know vaguely that the ^ character is involved, however I have not really a clue how to formalate that 

This is a good one. Added bonus: easy to modify to get rid of the comma as well.

To replace the comma too, use [ "" ] "" , ""

Unfortunately the stringpairreplacer is not very legible when replacing single characters like this. You can vote for my improvement idea here https://knowledge.safe.com/idea/81295/stringpairreplacer-interface-improvements.html

@egomm wow that is a nice alternative, Is it possible to include symbols? I would like to add parentheses around a number for example, thus Park5 will become Park(5) or should I use the StringReplacer for that?

I suspect you'll need the StringSearcher for that one, as the StringPairReplacer is about replacing known characters. You can try this:

Text to replace:

(\d+)

Replacement text:

(\1)

(\d+)

(\1)

@ david_r , for some reason after doing all the steps mentioned before

1) deleting square brackets in stringpairreplacer

2) deleting comma's in stringpairreplacer

3) and surrounding parentheses around the numbers in stringreplacer

I get the following output in the other software when I importing the column,

The square brackets in this case, is due to the fact that I am reading the column in the software as lists, therefore the squarebrackets. If I didn't remove the squarebrackets beforehand in FME, there would have been list in another list. 

However as you can see, instead of 'Park(5)','Park(4)' I get thus the thing above in the picture. So I was wondering how I could prevent the seperate entities as in the above picture

What format are you writing to? It sounds like something that's being inserted on writing and may be controlled by a parameter in the writer. I presume if you hook up an inspector to the stringreplacer and look at the attributes they don't have the quote marks?

@egomm Yes when I look at inspector, there areindeed no quotation marks. When I delete the square brackets and the comma, then this problem doesn't occure. It's only after including the parentheses, that this does occur. In case when it has to do with a parameter in the writer, do you have by any chance an idea about which parameter it might be the case?