将分组的熊猫数据应用回原始数据框

时间:2019-02-27 21:34:20

标签: python pandas

我下面正在使用的数据框:

这些是国际象棋游戏,我试图按游戏进行分组,然后根据该游戏中的下棋次数在每个游戏上执行功能...

        game_id     move_number colour  avg_centi
0       03gDhPWr    1           white   NaN
1       03gDhPWr    2           black   37.0
2       03gDhPWr    3           white   61.0
3       03gDhPWr    4           black   -5.0
4       03gDhPWr    5           white   26.0
5       03gDhPWr    6           black   31.0
6       03gDhPWr    7           white   -2.0
... ... ... ... ...
110091  zzaiRa7s    34          black   NaN
110092  zzaiRa7s    35          white   NaN
110093  zzaiRa7s    36          black   NaN
110094  zzaiRa7s    37          white   NaN
110095  zzaiRa7s    38          black   NaN
110096  zzaiRa7s    39          white   NaN
110097  zzaiRa7s    40          black   NaN

具体来说,我正在使用pd.cut创建一个新列game_phase,该列列出了给定的举动是在开局,中局还是残局中进行的。

我正在使用以下代码来实现这一目标。请注意,每个游戏都必须根据该游戏中的总移动次数分为openingmiddlegameendgame箱。

def define_move_phase(x):
    bins = (0, round(x['move_number'].max() * 1/3), round(x['move_number'].max() * 2/3), x['move_number'].max())    
    phases = ["opening", "middlegame", "endgame"]
    try:
        x.loc[:, 'phase'] = pd.cut(x['move_number'], bins, labels=phases)
    except ValueError:
        x.loc[:, 'phase'] = None
    print(x)

df.groupby('game_id').apply(define_move_phase)

该函数中的print语句表明该函数正在各个组上工作(请参见下文),但不会将phase列应用于原始数据框。

     game_id  move_number colour  avg_centi    phase
0   03gDhPWr            1  white        NaN  opening
1   03gDhPWr            2  black       37.0  opening
2   03gDhPWr            3  white       61.0  opening
3   03gDhPWr            4  black       -5.0  opening
4   03gDhPWr            5  white       26.0  opening
5   03gDhPWr            6  black       31.0  opening
6   03gDhPWr            7  white       -2.0  opening
..       ...          ...    ...        ...      ...
54  03gDhPWr           55  white       58.0  endgame
55  03gDhPWr           56  black       26.0  endgame
56  03gDhPWr           57  white      116.0  endgame
57  03gDhPWr           58  black     2000.0  endgame
58  03gDhPWr           59  white        0.0  endgame
59  03gDhPWr           60  black        0.0  endgame
60  03gDhPWr           61  white        NaN  endgame

[61 rows x 5 columns]
     game_id  move_number colour  avg_centi    phase
0   03gDhPWr            1  white        NaN  opening
1   03gDhPWr            2  black       37.0  opening
2   03gDhPWr            3  white       61.0  opening
3   03gDhPWr            4  black       -5.0  opening
4   03gDhPWr            5  white       26.0  opening
5   03gDhPWr            6  black       31.0  opening
6   03gDhPWr            7  white       -2.0  opening
..       ...          ...    ...        ...      ...
54  03gDhPWr           55  white       58.0  endgame
55  03gDhPWr           56  black       26.0  endgame
56  03gDhPWr           57  white      116.0  endgame
57  03gDhPWr           58  black     2000.0  endgame
58  03gDhPWr           59  white        0.0  endgame
59  03gDhPWr           60  black        0.0  endgame
60  03gDhPWr           61  white        NaN  endgame

[61 rows x 5 columns]

等...

我想将新的phase列应用于原始数据帧,或者再次将已分组的数据帧取消分组为一个大数据帧。这样做的最佳方法是什么?

1 个答案:

答案 0 :(得分:1)

您的函数没有return语句