从拆分索引获得的分组值

Question

我需要找到最多两列（p_1_logreg，p_2_logreg），其中比较应该仅限于14行。

My csv file

我试图将我的索引切成：

    int1_str1_str2_int2_str3_int4

应该在行之间找到max，其中int1，str1，str2，int2和str3是固定的，只有int4会改变（从索引0到索引13，依此类推）。

我试图一次修复每个元素并使用groupby，但我无法迭代int4值。

以下是查找列p_1_label的最大值的代码，但结果不是我要查找的内容。

    max_1_row=raw_prob.loc[raw_prob.groupby(raw_prob['id'].str.split('_').str[1])['p_1_'+label].idxmax()]

    max_1_row=max_1_row.loc[raw_prob.groupby(raw_prob['id'].str.split('_').str[3])['p_1_'+label].idxmax()]

    max_1_row=max_1_row.loc[raw_prob.groupby(raw_prob['id'].str.split('_').str[5])['p_1_'+label].idxmax()]

有任何想法吗？

Answer 1

我认为你需要DataFrameGroupBy.idxmax用空字符串替换最后的_然后由loc选择：

df = pd.read_csv('myProb.csv', index_col=[0])

idx = df.drop('id', 1).groupby(df['id'].str.replace('_\d+$', '')).idxmax()
print (idx.head(15))
                              p_0_logreg  p_1_logreg  p_2_logreg
id                                                              
6_PanaCleanerJune_sub_12_ICA           2           9           6
6_PanaCleanerJune_sub_13_ICA          17          19          23
6_PanaCleanerJune_sub_14_ICA          34          37          33
6_PanaCleanerJune_sub_15_ICA          52          51          43
6_PanaCleanerJune_sub_17_ICA          66          67          69
6_PanaCleanerJune_sub_18_ICA          82          79          76
6_PanaCleanerJune_sub_19_ICA          89          87          90
6_PanaCleanerJune_sub_20_ICA          98         103         104
6_PanaCleanerJune_sub_21_ICA         114         117         112
6_PanaCleanerJune_sub_22_ICA         129         133         127
6_PanaCleanerJune_sub_23_ICA         145         146         143
6_PanaCleanerJune_sub_24_ICA         155         166         161
6_PanaCleanerJune_sub_25_ICA         176         173         174
6_PanaCleanerJune_sub_26_ICA         186         191         189
6_PanaCleanerJune_sub_27_ICA         202         203         209

---

df1 = df.loc[idx['p_1_logreg']]
print (df1.head(15))
                                  id  p_0_logreg  p_1_logreg  p_2_logreg
9    6_PanaCleanerJune_sub_12_ICA_10    0.013452    0.985195    0.001353
19    6_PanaCleanerJune_sub_13_ICA_6    0.051184    0.948816    0.000000
37   6_PanaCleanerJune_sub_14_ICA_10    0.013758    0.979351    0.006890
51   6_PanaCleanerJune_sub_15_ICA_10    0.076056    0.923944    0.000000
67   6_PanaCleanerJune_sub_17_ICA_12    0.051060    0.947660    0.001280
79   6_PanaCleanerJune_sub_18_ICA_10    0.051184    0.948816    0.000000
87    6_PanaCleanerJune_sub_19_ICA_4    0.078162    0.917751    0.004087
103   6_PanaCleanerJune_sub_20_ICA_6    0.076400    0.921263    0.002337
117   6_PanaCleanerJune_sub_21_ICA_6    0.155002    0.791753    0.053245
133   6_PanaCleanerJune_sub_22_ICA_8    0.000000    0.998623    0.001377
146   6_PanaCleanerJune_sub_23_ICA_7    0.017549    0.973995    0.008457
166  6_PanaCleanerJune_sub_24_ICA_13    0.025215    0.974785    0.000000
173   6_PanaCleanerJune_sub_25_ICA_6    0.025656    0.960220    0.014124
191  6_PanaCleanerJune_sub_26_ICA_10    0.098872    0.895526    0.005602
203   6_PanaCleanerJune_sub_27_ICA_8    0.066493    0.932470    0.001037

---

df2 = df.loc[idx['p_2_logreg']]
print (df2.head(15))
                                  id  p_0_logreg  p_1_logreg  p_2_logreg
6     6_PanaCleanerJune_sub_12_ICA_7    0.000000    0.000351    0.999649
23   6_PanaCleanerJune_sub_13_ICA_10    0.000000    0.000351    0.999649
33    6_PanaCleanerJune_sub_14_ICA_6    0.080748    0.000352    0.918900
43    6_PanaCleanerJune_sub_15_ICA_2    0.017643    0.000360    0.981996
69   6_PanaCleanerJune_sub_17_ICA_14    0.882449    0.000290    0.117261
76    6_PanaCleanerJune_sub_18_ICA_7    0.010929    0.000360    0.988711
90    6_PanaCleanerJune_sub_19_ICA_7    0.010929    0.000351    0.988720
104   6_PanaCleanerJune_sub_20_ICA_7    0.006714    0.000360    0.992925
112   6_PanaCleanerJune_sub_21_ICA_1    0.869393    0.000339    0.130269
127   6_PanaCleanerJune_sub_22_ICA_2    0.000000    0.000351    0.999649
143   6_PanaCleanerJune_sub_23_ICA_4    0.017218    0.000360    0.982421
161   6_PanaCleanerJune_sub_24_ICA_8    0.369685    0.000712    0.629603
174   6_PanaCleanerJune_sub_25_ICA_7    0.307056    0.000496    0.692448
189   6_PanaCleanerJune_sub_26_ICA_8    0.850195    0.000368    0.149437
209  6_PanaCleanerJune_sub_27_ICA_14    0.000000    0.000351    0.999649

详情：

print (df['id'].str.replace('_\d+$', '').head(15))
0     6_PanaCleanerJune_sub_12_ICA
1     6_PanaCleanerJune_sub_12_ICA
2     6_PanaCleanerJune_sub_12_ICA
3     6_PanaCleanerJune_sub_12_ICA
4     6_PanaCleanerJune_sub_12_ICA
5     6_PanaCleanerJune_sub_12_ICA
6     6_PanaCleanerJune_sub_12_ICA
7     6_PanaCleanerJune_sub_12_ICA
8     6_PanaCleanerJune_sub_12_ICA
9     6_PanaCleanerJune_sub_12_ICA
10    6_PanaCleanerJune_sub_12_ICA
11    6_PanaCleanerJune_sub_12_ICA
12    6_PanaCleanerJune_sub_12_ICA
13    6_PanaCleanerJune_sub_12_ICA
14    6_PanaCleanerJune_sub_13_ICA
Name: id, dtype: object