Python pkg_resources 模块，evaluate_marker() 实例源码

def marker_passes(marker):
        """
        Given an environment marker, return True if the marker is valid
        and matches this environment.
        """
        return (
            not marker
            or not pkg_resources.invalid_marker(marker)
            and pkg_resources.evaluate_marker(marker)
        )

def test_ordering(python_version_mock):
    assert evaluate_marker("python_full_version > '2.7.3'") is True

def test_ordering(python_version_mock):
    assert evaluate_marker("python_full_version > '2.7.3'") is True

def test_ordering(python_version_mock):
    assert evaluate_marker("python_full_version > '2.7.3'") is True