def test_memory_usage_dataframe():
np.random.seed(0)
df = DataFrame()
nelem = 1000
df["keys"] = hkeys = np.arange(nelem, dtype=np.float64)
df["vals"] = hvals = np.random.random(nelem)
nbytes = hkeys.nbytes + hvals.nbytes
sizeof = df.memory_usage().sum()
assert sizeof >= nbytes
serialized_nbytes = len(pickle.dumps(df, protocol=pickle.HIGHEST_PROTOCOL))
# assert at least sizeof bytes were serialized
assert serialized_nbytes >= sizeof
