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 draw():
    global theta
    context.clearRect(0, 0, canvas.width, canvas.height)
    line1.drawMe(context)
    line2.drawMe(context)
    line3.drawMe(context)
    #triangle1.drawMe(context)
    #triangle2.drawMe(context)
    theta += dx
    p2.x = p1.x + line1.length*math.cos(theta*degree)
    p2.y = p1.y - line1.length*math.sin(theta*degree)
    p3.x, p3.y = triangle2.setPPSS(p2,p4,link2_len,link3_len)
    p1.tag(context)