def get_python_argv(self):
        """
        Return the initial argument vector elements necessary to invoke Python,
        by returning a 1-element list containing :attr:`python_path` if it is a
        string, or simply returning it if it is already a list.

        This allows emulation of existing tools where the Python invocation may
        be set to e.g. `['/usr/bin/env', 'python']`.
        """
        if isinstance(self.python_path, list):
            return self.python_path
        return [self.python_path]