使用熊猫按日对数据框进行分组

时间:2018-12-11 14:03:43

标签: python pandas python-2.7 dataframe

我有一个数据框,格式为:

      user                    accuracy  latitude  longitude      timestamp
0   5573502c150000c10136e51b    29.942 -8.658122 -45.700106  1434127670836
1   5573502c150000c10136e51b    30.000 -8.658068 -45.700127  1434127730889
2   5573502c150000c10136e51b    30.000 -8.658068 -45.700127  1434127790911
3   5573502c150000c10136e51b    30.000 -8.658057 -45.700123  1434127858915
4   5573502c150000c10136e51b    39.000 -8.658072 -45.700108  1434127918948
5   5573502c150000c10136e51b    31.876 -8.658100 -45.700107  1434128021062
6   5573502c150000c10136e51b    30.048 -8.658116 -45.700140  1434128151467
7   5573502c150000c10136e51b    30.473 -8.658118 -45.700097  1434128277097
8   5573502c150000c10136e51b    55.500 -6.658087 -45.700138  1434140105618
9   5573502c150000c10136e51b    55.500 -6.658087 -45.700138  1434140165685
10  5573502c150000c10136e51b    30.000 -6.658057 -45.700130  1434140225898
11  5573502c150000c10136e51b    30.000 -6.658057 -45.700130  1434140285952
12  5573502c150000c10136e51b    30.000 -7.658084 -45.700113  1434140346166
13  5573502c150000c10136e51b    36.000 -7.658051 -45.700138  1434140406214
14  5573502c150000c10136e51b    36.000 -5.658051 -45.700138  1434140466240
15  5573502c150000c10136e51b    32.908 -5.658091 -45.700097  1434140526278
16  5573502c150000c10136e51b    32.908 -5.658091 -45.700097  1434140586325
17  5573502c150000c10136e51b    34.009 -5.658075 -45.700119  1434140646363
18  5573502c150000c10136e51b    30.000 -5.658058 -45.700118  1434140706409
19  5573502c150000c10136e51b    30.000 -5.658058 -45.700118  1434140766455

我想按天对数据框进行分组,然后将每天的记录追加到其他列表中。

真是的,我有

DFList = [group[1] for group in df.groupby(df.index.day)]
print DFList

但是我得到一个错误:

  

AttributeError:“ RangeIndex”对象没有属性“ day”

有人知道如何解决此问题吗?

1 个答案:

答案 0 :(得分:3)

我认为您首先需要to_datetimeunit='ms',然后转换为Series.dt.day

df['day'] = pd.to_datetime(df['timestamp'], unit='ms').dt.day

dfs = [x for i, x in df.groupby('day')]

或者如果需要DatetimeIndex

df['timestamp'] = pd.to_datetime(df['timestamp'], unit='ms')
df = df.set_index('timestamp')
dfs = [x for i, x in df.groupby(df.index.day)]
print (dfs)

如果需要相同格式的时间戳列:

day = pd.to_datetime(df['timestamp'], unit='ms').dt.day

dfs = [x for i, x in df.groupby(day)]