def test_drop_obs_column():
    adata = ad.AnnData(np.array(X_list), obs=obs_dict, dtype="int32")

    subset = adata[:2]
    assert subset.is_view
    # returns a copy of obs
    assert subset.obs.drop(columns=["oanno1"]).columns.tolist() == ["oanno2", "oanno3"]
    assert subset.is_view
    # would modify obs, so it should actualize subset and not modify adata
    subset.obs.drop(columns=["oanno1"], inplace=True)
    assert not subset.is_view
    assert subset.obs.columns.tolist() == ["oanno2", "oanno3"]

    assert adata.obs.columns.tolist() == ["oanno1", "oanno2", "oanno3"]
def test_reverse_rfc822_datetime():
    dates = [
        ("Sat, 01 Jan 2011 00:00:00 -0000", datetime(2011, 1, 1, tzinfo=pytz.utc)),
        ("Sat, 01 Jan 2011 23:59:59 -0000", datetime(2011, 1, 1, 23, 59, 59, tzinfo=pytz.utc)),
        ("Sat, 01 Jan 2011 21:59:59 -0200", datetime(2011, 1, 1, 23, 59, 59, tzinfo=pytz.utc)),
    ]

    for date_string, expected in dates:
        yield assert_equal, inputs.datetime_from_rfc822(date_string), expected