def test_as_string(self):
a = Vector([1, 2]).as_string()
assert a.is_string()
assert np.all(a == ["1", "2"])
def test___new___na_string(self):
# Missing values should be blank strings.
a = Vector(["a", "b", "", NaN, None])
b = Vector(["a", "b", "", "", ""])
assert a.is_string()
assert a.equal(b)
