Pandas系列值包含列表，如何计算唯一值并将其作为字典返回

import pandas as pd

series = pd.Series([1, 2, 3, 2, 1, 3, 4])

unique_values = series.unique()

unique_dict = {}

for i, value in enumerate(unique_values):
    unique_dict[value] = i

import pandas as pd

series = pd.Series([1, 2, 3, 2, 1, 3, 4])
unique_values = series.unique()

unique_dict = {}
for i, value in enumerate(unique_values):
    unique_dict[value] = i

print(unique_dict)

{1: 0, 2: 1, 3: 2, 4: 3}