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 exceptions_log_path(cls, for_pid=None, in_dir=None):
        """Get the path to either the shared or pid-specific fatal errors log file."""
        if for_pid is None:
            intermediate_filename_component = ""
        else:
            assert isinstance(for_pid, Pid)
            intermediate_filename_component = ".{}".format(for_pid)
        in_dir = in_dir or cls._log_dir
        return os.path.join(
            in_dir, ".pids", "exceptions{}.log".format(intermediate_filename_component)
        )