Return string type user input

def get_string(self, input_string):
        """
		Return string type user input
		"""

        if input_string in ('--input', '--outname', '--framework'):

            # was the flag set?
            try:
                index = self.args.index(input_string) + 1
            except ValueError:
                # it wasn't, so if it's required, exit
                if input_string in self.required:
                    print("\n {flag} is required".format(input_string))
                    print_short_help()
                    sys.exit(1)
                # it wasn't, if its optional, return the default
                else:
                    return None

                    # the flag was set, so check if a value was set, otherwise exit
            try:
                if self.args[index] in self.flags:
                    print("\n {flag} was set but a value was not specified".format(flag=input_string))
                    print_short_help()
                    sys.exit(1)
            except IndexError:
                print("\n {flag} was set but a value was not specified".format(input_string))
                print_short_help()
                sys.exit(1)

            # a value was set, so check and assign the appropriate value or exit
            if input_string == '--input':
                return os.path.abspath(self.args[index])
            elif input_string == '--outname':
                return format(self.args[index])