Compare Abinit version to `version_string` with operator `op`

def compare_version(self, version_string, op):
        """Compare Abinit version to `version_string` with operator `op`"""
        from pkg_resources import parse_version
        from monty.operator import operator_from_str
        op = operator_from_str(op)
        return op(parse_version(self.version), parse_version(version_string))