Python df按日期添加行，因此每个组在同一日期结束。填充剩余行

import pandas as pd
import numpy as np

df = pd.DataFrame(columns=['日期', '组', '数值'])

start_date = pd.to_datetime('2022-01-01')
end_date = pd.to_datetime('2022-01-31')
num_groups = 5

dates = pd.date_range(start_date, end_date)
groups = np.repeat(range(1, num_groups + 1), len(dates) // num_groups)

for date, group in zip(dates, groups):
    df = df.append({'日期': date, '组': group, '数值': np.nan}, ignore_index=True)

df['数值'] = df.groupby('组')['数值'].ffill()

import pandas as pd
import numpy as np

df = pd.DataFrame(columns=['日期', '组', '数值'])

start_date = pd.to_datetime('2022-01-01')
end_date = pd.to_datetime('2022-01-31')
num_groups = 5

dates = pd.date_range(start_date, end_date)
groups = np.repeat(range(1, num_groups + 1), len(dates) // num_groups)

for date, group in zip(dates, groups):
    df = df.append({'日期': date, '组': group, '数值': np.nan}, ignore_index=True)

df['数值'] = df.groupby('组')['数值'].ffill()

print(df)