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 __init__(self, filename, errors):
        """
        :param filename: The name of the transaction file being replayed
        :param errors: a list of error classes or a string with an error description
        """

        # store args in case someone wants to read them from a caught exception
        self.filename = filename
        if isinstance(errors, (list, tuple)):
            self.errors = errors
        else:
            self.errors = [errors]

        if filename:
            msg = _('The following problems occurred while replaying the transaction from file "{filename}":').format(filename=filename)
        else:
            msg = _('The following problems occurred while running a transaction:')

        for error in self.errors:
            msg += "\n  " + str(error)

        super(TransactionReplayError, self).__init__(msg)