小编Mal*_*hai的帖子

pandas 开发新手。如何使用先前看到的列中包含的值向前填充 DataFrame？

独立的示例：

import pandas as pd
import numpy as np
O = [1, np.nan, 5, np.nan]
H = [5, np.nan, 5, np.nan]
L = [1, np.nan, 2, np.nan]
C = [5, np.nan, 2, np.nan]
timestamps = ["2017-07-23 03:13:00", "2017-07-23 03:14:00", "2017-07-23 03:15:00", "2017-07-23 03:16:00"]
dict = {'Open': O, 'High': H, 'Low': L, 'Close': C}
df = pd.DataFrame(index=timestamps, data=dict)
ohlc = df[['Open', 'High', 'Low', 'Close']]

这会产生以下数据帧：

print(ohlc)
                     Open  High  Low  Close
2017-07-23 03:13:00   1.0   5.0  1.0    5.0
2017-07-23 03:14:00 …