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 _loadapp(self, proxy_config_path):
        """
        Load a proxy from an app.conf to get the memcache_ring

        :returns: the memcache_ring of the memcache middleware filter
        """
        with mock.patch('swift.proxy.server.Ring'):
            app = loadapp(proxy_config_path)
        memcache_ring = None
        while True:
            memcache_ring = getattr(app, 'memcache', None)
            if memcache_ring:
                break
            app = app.app
        return memcache_ring