【Python】unique v.s. nunique

import numpy as np

arr = np.array([2, 4, 2, 5, 3, 5, 1, 1, 0, 5])

unique_arr = np.unique(arr)

print(unique_arr)

# output: [0 1 2 3 4 5]

import pandas as pd

# create a sample pandas

Seriesdata = pd.Series([1, 2, 2, 3, 3, 3, None])

# compute the number of unique values in the Series

num_unique = data.nunique()

print(num_unique)

# output: 3