熊猫中的多维/嵌套数据框/数据集/面板


问题内容

我想在熊猫数据框或面板中存储一些多维数据,以便能够返回例如:

  1. 一直都是A赛跑者
  2. 某年(例如2015年)A种族的所有时间(和名字)

示例数据看起来像这样,请注意,并非所有跑步者都会获得所有年份或所有种族的数据。

有人可以建议用Pandas或其他方式来做到这一点的好方法吗?

Name     | Gender | Age
Runner A | Male   | 35
    Race A
        Year | Time     
        2015 | 2:35:09  
        2014 | 2:47:34
        2013 | 2:50:12
    Race B
        Year | Time
        2013 | 1:32:07

Runner B | Male | 29
    Race A
        Year | Time
        2015 | 3:05:56

Runner C | Female | 32
    Race B
        Year | Time
        1998 | 1:29:43

问题答案:

我认为您可以使用Multiindex,然后通过切片器选择数据:

import pandas as pd

df = pd.DataFrame({'Time': {('Runner A', 'Male', 35, 'Race A', 2014): '2:47:34', ('Runner C', 'Female', 32, 'Race B', 1998): '1:29:43', ('Runner B', 'Male', 29, 'Race A', 2015): '3:05:56', ('Runner A', 'Male', 35, 'Race A', 2013): '2:50:12', ('Runner A', 'Male', 35, 'Race B', 2013): '1:32:07', ('Runner A', 'Male', 35, 'Race A', 2015): '2:35:09'}})
print (df)
                                   Time
Runner A Male   35 Race A 2013  2:50:12
                          2014  2:47:34
                          2015  2:35:09
                   Race B 2013  1:32:07
Runner B Male   29 Race A 2015  3:05:56
Runner C Female 32 Race B 1998  1:29:43

#index has to be fully lexsorted
df.sort_index(inplace=True)
print (df)
                                   Time
Runner A Male   35 Race A 2013  2:50:12
                          2014  2:47:34
                          2015  2:35:09
                   Race B 2013  1:32:07
Runner B Male   29 Race A 2015  3:05:56
Runner C Female 32 Race B 1998  1:29:43

idx = pd.IndexSlice
print (df.loc[idx['Runner A',:,:,'Race A',:],:])
                                 Time
Runner A Male 35 Race A 2013  2:50:12
                        2014  2:47:34
                        2015  2:35:09

print (df.loc[idx[:,:,:,'Race A',2015],:])
                                 Time
Runner A Male 35 Race A 2015  2:35:09
Runner B Male 29 Race A 2015  3:05:56