'Extracts the exception line from the input string, and marks
the location of the exception with a special symbol.'

def markInputline(self, markerString='>!<'):

    line_str = self.line
    line_column = (self.column - 1)
    if markerString:
        line_str = ''.join([line_str[:line_column], markerString, line_str[line_column:]])
    return line_str.strip()
