嵌套 for 循环 pandas 数据框不创建新列

Question

我有这个嵌套循环：

rolling=['10','20']

for i in range(len(ex)):
    for d in rolling:
       df = nested_df.loc[other_nested_df['pio'][i]:(other_nested_df['pio'][i]+10)].copy()
       ex.loc[i]['date_vert_'+str(d)=df['date'].iloc[-1]

循环没有给出任何错误，但我不明白为什么最后数据帧 ex 没有其他两列称为 date_vert_10 和 date_vert_20

Answer 1

将ex.loc[i][...]改为ex.loc[i, ...]:

rolling=['10','20']

for i in range(len(ex)):
    for d in rolling:
       df = nested_df.loc[other_nested_df['pio'][i]:(other_nested_df['pio'][i]+10)].copy()
       ex.loc[i, 'date_vert_'+str(d)=df['date'].iloc[-1]
       # ^^^^^^^^^^^ changed