pandas 如何按时间间隔按列拆分数据帧 [英] Pandas how to split dataframe by column by interval

问题描述

我有一个巨大的数据框，其中的日期时间类型列称为dt，该数据框已经基于dt进行了排序.我想根据dt将数据帧分为几个数据帧，每个数据帧包含1 hr范围内的行.

I have a gigantic dataframe with a datetime type column called dt, the data frame is sorted based on dt already. I want to split the dataframe into several dataframes based on dt, each dataframe contains rows within 1 hr range.

拆分

   dt                    text
0  20160811 11:05        a
1  20160811 11:35        b
2  20160811 12:03        c
3  20160811 12:36        d
4  20160811 12:52        e
5  20160811 14:32        f

进入

   dt                    text
0  20160811 11:05        a
1  20160811 11:35        b
2  20160811 12:03        c

   dt                    text
0  20160811 12:36        d
1  20160811 12:52        e

   dt                    text 
0  20160811 14:32        f

推荐答案

您需要 groupby 由 List comprehension解决方案:

S = pd.to_datetime(df.dt)

print ((S - S[0]).astype('timedelta64[h]'))
0    0.0
1    0.0
2    0.0
3    1.0
4    1.0
5    3.0
Name: dt, dtype: float64

L = [g.reset_index(drop=True) for i, g in df.groupby([(S - S[0]).astype('timedelta64[h]')])]

print (L[0])
               dt text
0  20160811 11:05    a
1  20160811 11:35    b
2  20160811 12:03    c

print (L[1])
               dt text
0  20160811 12:36    d
1  20160811 12:52    e

print (L[2])
               dt text
0  20160811 14:32    f

---

旧解决方案，由hour分开:

---

Old solution, which split by hour:

您可以使用 groupby 由 dt.hour 提出，但首先需要转换dt to_datetime :

You can use groupby by dt.hour, but first need convert dt to_datetime:

for i, g in df.groupby([pd.to_datetime(df.dt).dt.hour]):
    print (g.reset_index(drop=True))

               dt text
0  20160811 11:05    a
1  20160811 11:35    b
               dt text
0  20160811 12:03    c
1  20160811 12:36    d
2  20160811 12:52    e
               dt text
0  20160811 14:32    f

List comprehension解决方案:

L = [g.reset_index(drop=True) for i, g in df.groupby([pd.to_datetime(df.dt).dt.hour])]

print (L[0])
               dt text
0  20160811 11:05    a
1  20160811 11:35    b

print (L[1])
               dt text
0  20160811 12:03    c
1  20160811 12:36    d
2  20160811 12:52    e

print (L[2])
               dt text
0  20160811 14:32    f

---

或使用list comprehension将列dt转换为datetime:

---

Or use list comprehension with converting column dt to datetime:

df.dt = pd.to_datetime(df.dt)
L =[g.reset_index(drop=True) for i, g in df.groupby([df['dt'].dt.hour])]

print (L[1])
                   dt text
0 2016-08-11 12:03:00    c
1 2016-08-11 12:36:00    d
2 2016-08-11 12:52:00    e

print (L[2])
                   dt text
0 2016-08-11 14:32:00    f

---

如果需要除以date s和hour s:

---

If need split by dates and hours:

#changed dataframe for testing
print (df)
               dt text
0  20160811 11:05    a
1  20160812 11:35    b
2  20160813 12:03    c
3  20160811 12:36    d
4  20160811 12:52    e
5  20160811 14:32    f

serie = pd.to_datetime(df.dt)
for i, g in df.groupby([serie.dt.date, serie.dt.hour]):
    print (g.reset_index(drop=True))
               dt text
0  20160811 11:05    a
               dt text
0  20160811 12:36    d
1  20160811 12:52    e
               dt text
0  20160811 14:32    f
               dt text
0  20160812 11:35    b
               dt text
0  20160813 12:03    c    

这篇关于 pandas 如何按时间间隔按列拆分数据帧的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！