def test_views():
    X = np.array(X_list)
    adata = ad.AnnData(X, obs=obs_dict, var=var_dict, uns=uns_dict, dtype="int32")

    assert adata[:, 0].is_view
    assert adata[:, 0].X.tolist() == np.reshape([1, 4, 7], (3, 1)).tolist()

    adata[:2, 0].X = [0, 0]

    assert adata[:, 0].X.tolist() == np.reshape([0, 0, 7], (3, 1)).tolist()

    adata_subset = adata[:2, [0, 1]]

    assert adata_subset.is_view
    # now transition to actual object
    adata_subset.obs["foo"] = range(2)
    assert not adata_subset.is_view

    assert adata_subset.obs["foo"].tolist() == list(range(2))
def _db_schema_sanity_check(engine):
    """Ensure all database tables were created with required parameters.

    :param engine:  SQLAlchemy engine instance for a given database

    """

    if engine.name == 'mysql':
        onlyutf8_sql = ('SELECT TABLE_NAME,TABLE_COLLATION '
                        'from information_schema.TABLES '
                        'where TABLE_SCHEMA=%s and '
                        'TABLE_COLLATION NOT LIKE "%%utf8%%"')

        table_names = [res[0] for res in engine.execute(onlyutf8_sql,
                                                        engine.url.database)]
        if len(table_names) > 0:
            raise ValueError(_('Tables "%s" have non utf8 collation, '
                               'please make sure all tables are CHARSET=utf8'
                               ) % ','.join(table_names))