How to extract substring in parentheses using Regex pattern

Question

This is probably a simple problem, but unfortunately I wasn\'t able to get the results I wanted...

Say, I have the following line:

\"Wouldn\'t It B         


        

Answer 1

Edit: After examining your document, the problem is that there are non-breaking spaces before the parentheses, not regular spaces. So this regex should work: ""[ \xA0]*\(([^)]+)\)

""       'quote (twice to escape)
[ \xA0]* 'zero or more non-breaking (\xA0) or a regular spaces
\(       'left parenthesis
(        'open capturing group
[^)]+    'anything not a right parenthesis
)        'close capturing group
\)       'right parenthesis

In a function:

Public Function GetStringInParens(search_str As String)
Dim regEx As New VBScript_RegExp_55.RegExp
Dim matches
    GetStringInParens = ""
    regEx.Pattern = """[ \xA0]*\(([^)]+)\)"
    regEx.Global = True
    If regEx.test(search_str) Then
        Set matches = regEx.Execute(search_str)
        GetStringInParens = matches(0).SubMatches(0)
    End If
End Function

Answer 2

This function worked on your example string:

Function GetArtist(songMeta As String) As String
  Dim artist As String
  ' split string by ")" and take last portion
  artist = Split(songMeta, "(")(UBound(Split(songMeta, "(")))
  ' remove closing parenthesis
  artist = Replace(artist, ")", "")
End Function

Ex:

Sub Test()

  Dim songMeta As String

  songMeta = """Wouldn't It Be Nice"" (B. Wilson/Asher/Love)"

  Debug.Print GetArtist(songMeta)

End Sub

prints "B. Wilson/Asher/Love" to the Immediate Window.

It also solves the problem alan mentioned. Ex:

Sub Test()

  Dim songMeta As String

  songMeta = """Wouldn't (It Be) Nice"" (B. Wilson/Asher/Love)"

  Debug.Print GetArtist(songMeta)

End Sub

also prints "B. Wilson/Asher/Love" to the Immediate Window. Unless of course, the artist names also include parentheses.

Answer 3

I think you need a better data file ;) You might want to consider pre-processing the file to a temp file for modification, so that outliers that don't fit your pattern are modified to where they'll meet your pattern. It's a bit time consuming to do, but it is always difficult when a data file lacks consistency.

Answer 4

Not strictly an answer to your question, but sometimes, for things this simple, good ol' string functions are less confusing and more concise than Regex.

Function BetweenParentheses(s As String) As String
    BetweenParentheses = Mid(s, InStr(s, "(") + 1, _
        InStr(s, ")") - InStr(s, "(") - 1)
End Function

Usage:

Debug.Print BetweenParentheses("""Wouldn't It Be Nice"" (B. Wilson/Asher/Love)")
'B. Wilson/Asher/Love

EDIT @alan points our that this will falsely match the contents of parentheses in the song title. This is easily circumvented with a little modification:

Function BetweenParentheses(s As String) As String
    Dim iEndQuote As Long
    Dim iLeftParenthesis As Long
    Dim iRightParenthesis As Long

    iEndQuote = InStrRev(s, """")
    iLeftParenthesis = InStr(iEndQuote, s, "(")
    iRightParenthesis = InStr(iEndQuote, s, ")")

    If iLeftParenthesis <> 0 And iRightParenthesis <> 0 Then
        BetweenParentheses = Mid(s, iLeftParenthesis + 1, _
            iRightParenthesis - iLeftParenthesis - 1)
    End If
End Function

Usage:

Debug.Print BetweenParentheses("""Wouldn't It Be Nice"" (B. Wilson/Asher/Love)")
'B. Wilson/Asher/Love
Debug.Print BetweenParentheses("""Don't talk (yell)""")
' returns empty string

Of course this is less concise than before!

Answer 5

This a nice regex

".*\(([^)]*)

In VBA/VBScript:

Dim myRegExp, ResultString, myMatches, myMatch As Match
Dim myRegExp As RegExp
Set myRegExp = New RegExp
myRegExp.Pattern = """.*\(([^)]*)"
Set myMatches = myRegExp.Execute(SubjectString)
If myMatches.Count >= 1 Then
    Set myMatch = myMatches(0)
    If myMatch.SubMatches.Count >= 3 Then
        ResultString = myMatch.SubMatches(3-1)
    Else
        ResultString = ""
    End If
Else
    ResultString = ""
End If

This matches

Put Your Head on My Shoulder

in

"Don't Talk (Put Your Head on My Shoulder)"  

Update 1

I let the regex loose on your doc file and it matches as requested. Quite sure the regex is fine. I'm not fluent in VBA/VBScript but my guess is that's where it goes wrong

If you want to discuss the regex some further that's fine with me. I'm not eager to start digging into this VBscript API which looks arcane.

Given the new input the regex is tweaked to

".*".*\(([^)]*)

So that it doesn't falsely match (Put Your Head on My Shoulder) which appears inside the quotes.

Answer 6

This another Regex tested with a vbscript (?:\()(.*)(?:\)) Demo Here

---

Data = """Wouldn't It Be Nice"" (B. Wilson/Asher/Love)"
wscript.echo Extract(Data)
'---------------------------------------------------------------
Function Extract(Data)
Dim strPattern,oRegExp,Matches
strPattern = "(?:\()(.*)(?:\))"
Set oRegExp = New RegExp
oRegExp.IgnoreCase = True 
oRegExp.Pattern = strPattern
set Matches = oRegExp.Execute(Data) 
If Matches.Count > 0 Then Extract = Matches(0).SubMatches(0)
End Function
'---------------------------------------------------------------