Task: Text between
Python: 
from sys import argv






def textBetween( thisText, startString, endString ):
    try:
    	if startString is 'start':
    		startIndex = 0
    	else:
    		startIndex = thisText.index( startString ) 
    	
    	if not (startIndex >= 0):
    		return 'Start delimiter not found'
    	else:
        	if startString is not 'start':
        		startIndex = startIndex + len( startString )
        
        returnText = thisText[startIndex:]


    	if endString is 'end':
    		return returnText
    	else:
    		endIndex = returnText.index( endString )

    	if not (endIndex >= 0):
    		return 'End delimiter not found'
    	else:
        	returnText = returnText[:endIndex]

        return returnText
    except ValueError:
        return "Value error"

script, first, second, third = argv

thisText = first
startString = second
endString = third

print textBetween( thisText, startString, endString )

VB: Option Explicit

Private Const STRING_START As String = "Start"
Private Const STRING_END As String = "End"

Sub Main()
Dim Text As String, First As String, Last As String, Output As String

    Text = "Hello Rosetta Code world"
        First = "Hello "
            Last = " world"
    Output = "1- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "Hello Rosetta Code world"
        First = "Start"
            Last = " world"
    Output = Output & "2- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "Hello Rosetta Code world"
        First = "Hello "
            Last = "End"
    Output = Output & "3- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "</div><div style=\""chinese\"">你好嗎</div>..."
        First = "<div style=\""chinese\"">"
            Last = "</div>"
    Output = Output & "4- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "<text>Hello <span>Rosetta Code</span> world</text><table style=\""myTable\"">"
        First = "<text>"
            Last = "<table>"
    Output = Output & "5- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "<table style=\""myTable\""><tr><td>hello world</td></tr></table>"
        First = "<table>"
            Last = "</table>"
    Output = Output & "6- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "The quick brown fox jumps over the lazy other fox"
        First = "quick "
            Last = " fox"
    Output = Output & "7- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "One fish two fish red fish blue fish"
        First = "fish "
            Last = " red"
    Output = Output & "8- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "FooBarBazFooBuxQuux"
        First = "Foo"
            Last = "Foo"
    Output = Output & "9- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "</div><div style=\""chinese\"">你好嗎..."
        First = "<div style=\""chinese\"">"
            Last = "</div>"
    Output = Output & "10- " & Text_Between(Text, First, Last) & vbCrLf

    Text = ""
        First = "Start"
            Last = "End"
    Output = Output & "11- " & Text_Between(Text, First, Last) & vbCrLf

    Text = "Hello Rosetta Code world"
        First = "Start"
            Last = "End"
    Output = Output & "12- " & Text_Between(Text, First, Last)

    Debug.Print Output
End Sub

Private Function Text_Between(T$, F$, L$) As String
Dim i As Long
    i = InStr(T, L) + 1
    Select Case True
        Case T = "", F = "", InStr(T, F) = 0 And F <> STRING_START
            Text_Between = ""
        Case F = STRING_START And L = STRING_END
            Text_Between = T
        Case F = STRING_START
            Text_Between = Mid(T, 1, InStr(T, L) - 1)
        Case L = STRING_END, InStr(T, L) = 0, InStr(T, L) < InStr(T, F) And InStr(i, T, L) = 0
            Text_Between = Mid(T, Len(F) + InStr(T, F))
        Case F = L
            Text_Between = Mid(T, Len(F) + InStr(T, F), InStr(i, T, F) - Len(F) - 1)
        Case Else
            Text_Between = Mid(T, Len(F) + InStr(T, F), InStr(InStr(T, F), T, L) - (Len(F) + InStr(T, F)))
    End Select
End Function