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 _check_version(version, filename):
    major, minor = version.split('.')

    try:
        major = int(major)
    except ValueError as e:
        raise TransactionReplayError(
            filename,
            _('Invalid major version "{major}", number expected.').format(major=major)
        )

    try:
        int(minor)  # minor is unused, just check it's a number
    except ValueError as e:
        raise TransactionReplayError(
            filename,
            _('Invalid minor version "{minor}", number expected.').format(minor=minor)
        )

    if major != VERSION_MAJOR:
        raise IncompatibleTransactionVersionError(
            filename,
            _('Incompatible major version "{major}", supported major version is "{major_supp}".')
                .format(major=major, major_supp=VERSION_MAJOR)
        )