Pandas 'SeriesGroupBy' has no method 'apply', 'groups', or 'get_group'

[kevinhu]

Script used:

import pandas as pd

df: pd.DataFrame = pd.DataFrame([[1, 2], [3, 4]], columns=["a", "b"], index=["c", "d"])

grouped = df.groupby("a")["b"]
grouped_list = grouped.apply(list)

print(df)
print(grouped)
print(grouped_list)
print(grouped.groups)
print(grouped.get_group(1))