[Python / Pandas] DataFrameに対して`replace`で`None`に置き換えようとするとバグが発生する - Qiita

import pandas as pd import numpy as np indexes = [ datetime.datetime(2020, 1, 1, 11, 50), datetime.datetime(2020, 1, 1, 12, 50), datetime.datetime(2020, 1, 1, 12, 52), datetime.datetime(2020, 1, 1, 18, 50), datetime.datetime(2020, 1, 1, 19, 50), datetime.datetime(2020, 1, 1, 21, 50), ] df = pd.DataFrame({ 'high': [1, np.nan, 3, np.nan, np.nan, 11], 'close': [4, 5, 6, 7, np.nan, 2], 'memo': ['sign'