Strip at the last occurrence of special characters

[soumya123]

Hi,

I would like to truncate a column at the last occurrence of special characters.
For eg:

Is there any regex to do this?

[takbb]

Hi @soumya123 ,I don’t have a clear definition of “special characters” (I know what they are but don’t know definitively which characters you would treat as special characters) so I’m treating it as any “non-alphanumeric” characters. You can replace this with an specific set of characters if necessary.

I think the following describes in different words what I think you are trying to return:

A regex that will capture a string up to, but not including, an end marker
where the end marker is defined as :

(a) the first non-alphanumeric character ("special character") that is followed only by an optional number (0, 1 or many) of non-alpha numeric characters followed by a sequence of 0, 1 or many alphanumeric characters

or

(b) the line terminator

The following regex works in my tests, when used with the Regex Split node:

(.*?)([^a-zA-Z0-9][^a-zA-Z0-9]*[A-Za-z0-9]*|$)

notes:
(.*?) = string to be captured followed by
either
[^a-zA-Z0-9] = first non-alpha-numeric character followed by
[^a-zA-Z0-9]* = an optional sequence of non-alphanumeric characters followed by
[A-Za-z0-9]* = an optional sequence of alphanumeric characters
or
$ = the line terminator

truncate string at last special character onwards.knwf (11.0 KB)