到目前为止，将 daily_volume 添加到数据框 pandas答案

【问题标题】：Add daily_volume so far to dataframe pandas到目前为止，将 daily_volume 添加到数据框 pandas
【发布时间】：2020-10-09 01:27:08
【问题描述】：

我有以下一天的数据框，其中每一行是一分钟。：

stock,date,open,high,low,close,volume
AACG,202005010928,0.73,0.73,0.73,0.73,200
AACG,202005010929,0.73,0.73,0.73,0.73,100
AACG,202005010930,0.8,0.8,0.8,0.8,1250
AACG,202005010934,0.72,0.72,0.72,0.72,100
AACG,202005010937,0.71,0.71,0.68,0.68,3599
AACG,202005010938,0.65,0.65,0.65,0.65,2200
AACG,202005010947,0.73,0.73,0.73,0.73,125
AACG,202005010955,0.71,0.71,0.71,0.71,300
AACG,202005011002,0.7,0.7,0.7,0.7,10818
AACG,202005011112,0.73,0.73,0.73,0.73,100
AACG,202005011125,0.7,0.7,0.7,0.7,1103
AACG,202005011153,0.7,0.7,0.66,0.66,3334
AACG,202005011223,0.7,0.7,0.7,0.7,100
AACG,202005011234,0.73,0.73,0.73,0.73,250
AACG,202005011258,0.71,0.71,0.71,0.71,100
AACG,202005011321,0.73,0.73,0.72,0.72,1200
AACG,202005011329,0.7,0.7,0.7,0.7,4200
AACG,202005011427,0.73,0.73,0.73,0.73,100
AACG,202005011432,0.65,0.65,0.65,0.65,369
AACG,202005011529,0.66,0.66,0.66,0.66,254
AACG,202005011544,0.73,0.73,0.7,0.73,1397
AACG,202005011545,0.74,0.74,0.74,0.74,100
AACG,202005011548,0.73,0.73,0.73,0.73,100
AACG,202005011549,0.74,0.74,0.74,0.74,100
AAL,202005010900,11.29,11.3,11.29,11.29,8201
AAL,202005010901,11.28,11.31,11.26,11.28,26935
AAL,202005010902,11.3,11.34,11.3,11.33,31958
AAL,202005010903,11.33,11.36,11.31,11.35,44487
AAL,202005010904,11.35,11.35,11.32,11.33,22240

我想使用矢量方法（不是iterrows，因为这需要时间）为每一行添加一个计算迄今为止每日交易量的列。我怎样才能做到这一点？谢谢

【问题讨论】：

您正在寻找cumsum 我猜，如果您的数据框只包含一天，那么df['volume'].cumsum() 会这样做

标签： python pandas dataframe pandas-groupby pandas-apply

【解决方案1】：

df['cumsum'] = df['volume'].cumsum()

【讨论】：

代码只回答，没有解释或支持文档是不受欢迎的。 SO 是知识和学习的资源。竞争性、自包含的答案，引导读者推理他们的解决方案何时/为什么解决 OP 的问题具有更长期的价值，歪曲问答以突出知识，而不是给我代码编码服务类型的问题，并帮助未来的访问者将您的答案应用于他们自己的问题。最后，经过深思熟虑，带有解释的完整答案更有可能获得投票，因为它们对访问者的帮助最大。请考虑编辑以增加长期价值。

【解决方案2】：

按天按股票发行创建一个新的累积列。

df['date'] = pd.to_datetime(df['date'], format='%Y%m%d%H%M')
df['cumsum'] = df.groupby(['stock', df['date'].dt.date])['volume'].cumsum()

df
    stock   date    open    high    low close   volume  cumsum
0   AACG    2020-05-01 09:28:00 0.73    0.73    0.73    0.73    200 200
1   AACG    2020-05-01 09:29:00 0.73    0.73    0.73    0.73    100 300
2   AACG    2020-05-01 09:30:00 0.80    0.80    0.80    0.80    1250    1550
3   AACG    2020-05-01 09:34:00 0.72    0.72    0.72    0.72    100 1650
4   AACG    2020-05-01 09:37:00 0.71    0.71    0.68    0.68    3599    5249
5   AACG    2020-05-01 09:38:00 0.65    0.65    0.65    0.65    2200    7449
6   AACG    2020-05-01 09:47:00 0.73    0.73    0.73    0.73    125 7574
7   AACG    2020-05-01 09:55:00 0.71    0.71    0.71    0.71    300 7874
8   AACG    2020-05-01 10:02:00 0.70    0.70    0.70    0.70    10818   18692
9   AACG    2020-05-01 11:12:00 0.73    0.73    0.73    0.73    100 18792
10  AACG    2020-05-01 11:25:00 0.70    0.70    0.70    0.70    1103    19895
11  AACG    2020-05-01 11:53:00 0.70    0.70    0.66    0.66    3334    23229
12  AACG    2020-05-01 12:23:00 0.70    0.70    0.70    0.70    100 23329
13  AACG    2020-05-01 12:34:00 0.73    0.73    0.73    0.73    250 23579
14  AACG    2020-05-01 12:58:00 0.71    0.71    0.71    0.71    100 23679
15  AACG    2020-05-01 13:21:00 0.73    0.73    0.72    0.72    1200    24879
16  AACG    2020-05-01 13:29:00 0.70    0.70    0.70    0.70    4200    29079
17  AACG    2020-05-01 14:27:00 0.73    0.73    0.73    0.73    100 29179
18  AACG    2020-05-01 14:32:00 0.65    0.65    0.65    0.65    369 29548
19  AACG    2020-05-01 15:29:00 0.66    0.66    0.66    0.66    254 29802
20  AACG    2020-05-01 15:44:00 0.73    0.73    0.70    0.73    1397    31199
21  AACG    2020-05-01 15:45:00 0.74    0.74    0.74    0.74    100 31299
22  AACG    2020-05-01 15:48:00 0.73    0.73    0.73    0.73    100 31399
23  AACG    2020-05-01 15:49:00 0.74    0.74    0.74    0.74    100 31499
24  AAL 2020-05-01 09:00:00 11.29   11.30   11.29   11.29   8201    8201
25  AAL 2020-05-01 09:01:00 11.28   11.31   11.26   11.28   26935   35136
26  AAL 2020-05-01 09:02:00 11.30   11.34   11.30   11.33   31958   67094
27  AAL 2020-05-01 09:03:00 11.33   11.36   11.31   11.35   44487   111581
28  AAL 2020-05-01 09:04:00 11.35   11.35   11.32   11.33   22240   133821

【讨论】：