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 search(self, search_base=None, search_scope=None,
               search_filter=None, attributes=None, paged_size=5,
               size_limit=0, paged_cookie=None):
        s_filter = list()
        candidates = list()
        self.response = list()
        self.result = dict()

        try:
            if isinstance(search_filter, bytes):
                # We need to convert to unicode otherwise pyparsing will not
                # find the u"ö"
                search_filter = to_unicode(search_filter)
            expr = Connection._parse_filter()
            s_filter = expr.parseString(search_filter).asList()[0]
        except pyparsing.ParseBaseException as exx:
            # Just for debugging purposes
            s = "{!s}".format(exx)

        for item in s_filter:
            if item[0] in self.operation:
                candidates = self.operation.get(item[0])(search_base,
                                                         s_filter)
        self.response = Connection._deDuplicate(candidates)

        return True