无法对Pandas DataFrame中的特定行进行平均

时间:2015-08-03 09:33:13

标签: python datetime pandas dataframe average

我目前有以下两个DataFrame:

raw_data =

     Time                             F1         F2        F3
2082-05-03 00:00:59.961599999  -83.769997      29.430000      29.400000   
2082-05-03 00:02:00.009600000  -84.209999      28.940001      28.870001   
2082-05-03 00:02:59.971200000  -84.339996      28.280001      28.320000

outage_by_timeofday_num = (由raw_data制作)(忽略破折号 - 它们仅用于对齐)

                              F1     F2    F3  
Time                                                                        
2082-05-03 00:00:00           0      1     1   
2082-05-03 01:00:00           0      1     1  

我已经能够使用以下代码(下面)按时间对raw_data DataFrame进行排序和平均,但我无法对outage_by_timeofday_num DataFrame执行相同的操作:

这有效:

raw_data = pd.read_excel(r'/Users/linnk ....
raw_data[u'Time']= pd.to_datetime(raw_data['Time'], unit='d')    
raw_data.set_index(pd.DatetimeIndex(raw_data[u'Time']), inplace=True) 
raw_data.Time = pd.to_datetime(raw_data.Time)

def time_cat(t):
    hour = t.hour
    if(hour >= 5 and hour < 9):
        return 'Morning (5AM-9AM)'
    elif(hour >= 9 and hour < 18):
        return 'Day (9AM-6PM)'
    elif(hour >= 18 and hour < 22):
        return 'Evening (6PM-10PM)'
    else:
        return 'Night (10PM-5AM)'

by_timeofday = raw_data.groupby(raw_data.Time.apply(time_cat)).mean()

和by_timeofday输出为:

                        F1              F2             F3  
Time                                                                       
Day (9AM-6PM)         -47.301852      23.070963      22.981000   
Evening (6PM-10PM)    -50.033000      24.011667      23.921833   
Morning (5AM-9AM)     -62.481130      48.417866      48.537197   
Night (10PM-5AM)      -71.372613     -71.289763      53.957411 \

然而,这不起作用:

outage_by_hour_num.Time= pd.to_datetime(outage_by_hour_num.Time)
outage_by_timeofday = outage_by_hour_num.groupby(outage_by_hour_num.Time.apply(time_cat)).sum(axis=1, numeric_only=True)

这会出错: AttributeError:'DataFrame'对象没有属性'Time'

有人可以帮我发现我的错误/编辑我需要按照与排序raw_data相同的方式对outage_by_timeofday_num DataFrame进行排序吗? 如果它可能有用,则outage_by_timeofday_num按以下方式进行:

ave_data = raw_data.resample('h', how='mean')
ave_data.index.name=u'Time'
summary_ave_data = ave_data.copy()
summary_ave_data['Hourly Substation Average'] = summary_ave_data.mean(numeric_only=True, axis=1)
outage_by_hour = summary_ave_data >= 0.05
outage_by_hour_num= outage_by_hour.astype(int) 

1 个答案:

答案 0 :(得分:0)

您摆脱了ave_data.index.name=u'Time'中的“时间”列。 改为:

ave_data.set_index('Time', drop=False, inplace=True)

这确保您将其设置为索引,但保留“时间”列。