根据列给出一些行的权重

时间:2017-06-21 08:01:32

标签: python pandas select dataframe rows

这是我的数据框:

id   Year   Month   Day     Instant     Temperature     DayType     DayValidity     LoadNette   
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     
195     2008    4   5   3   8.07    6   1   51907.94746     
196     2008    5   5   4   8.03    6   1   50848.16566     

并且我希望复制5次我的数据帧,但是根据像这样的月份为某些行提供wieghts,例如,月份为4的行将仅复制3次,而第4次只有2次喜欢使用python:< / p>

id   Year   Month   Day     Instant     Temperature     DayType     DayValidity     LoadNette   
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     
195     2008    4   5   3   8.07    6   1   51907.94746     
196     2008    5   5   4   8.03    6   1   50848.16566
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     
195     2008    4   5   3   8.07    6   1   51907.94746     
196     2008    5   5   4   8.03    6   1   50848.16566
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     
195     2008    4   5   3   8.07    6   1   51907.94746     
196     2008    5   5   4   8.03    6   1   50848.16566
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     
195     2008    4   5   3   8.07    6   1   51907.94746     
192     2008    1   5   0   8.03    6   1   53039.77133     
193     2008    2   5   1   8.07    6   1   52200.71569     
194     2008    3   5   2   8.10    6   1   51681.17260     

有任何方法可以做到这一点

2 个答案:

答案 0 :(得分:3)

您可以使用dict来重复numpy.repeat和dict理解的次数:

d = {1:5, 2:2, 3:1, 4:3, 5:3}
l = df['Month'].map(d)
df = pd.DataFrame({col: np.repeat(df[col], l) for col in df.columns}, columns=df.columns)
print (df)
    id  Year  Month  Day  Instant  Temperature  DayType  DayValidity  \
0  192  2008      1    5        0         8.03        6            1   
0  192  2008      1    5        0         8.03        6            1   
0  192  2008      1    5        0         8.03        6            1   
0  192  2008      1    5        0         8.03        6            1   
0  192  2008      1    5        0         8.03        6            1   
1  193  2008      2    5        1         8.07        6            1   
1  193  2008      2    5        1         8.07        6            1   
2  194  2008      3    5        2         8.10        6            1   
3  195  2008      4    5        3         8.07        6            1   
3  195  2008      4    5        3         8.07        6            1   
3  195  2008      4    5        3         8.07        6            1   
4  196  2008      5    5        4         8.03        6            1   
4  196  2008      5    5        4         8.03        6            1   
4  196  2008      5    5        4         8.03        6            1   

     LoadNette  
0  53039.77133  
0  53039.77133  
0  53039.77133  
0  53039.77133  
0  53039.77133  
1  52200.71569  
1  52200.71569  
2  51681.17260  
3  51907.94746  
3  51907.94746  
3  51907.94746  
4  50848.16566  
4  50848.16566  
4  50848.16566  

另一种解决方案,如果需要使用concat重复所有行5次:

df = pd.concat([df] * 5, ignore_index=True)
print (df)
     id  Year  Month  Day  Instant  Temperature  DayType  DayValidity  \
0   192  2008      1    5        0         8.03        6            1   
1   193  2008      2    5        1         8.07        6            1   
2   194  2008      3    5        2         8.10        6            1   
3   195  2008      4    5        3         8.07        6            1   
4   196  2008      5    5        4         8.03        6            1   
5   192  2008      1    5        0         8.03        6            1   
6   193  2008      2    5        1         8.07        6            1   
7   194  2008      3    5        2         8.10        6            1   
8   195  2008      4    5        3         8.07        6            1   
9   196  2008      5    5        4         8.03        6            1   
10  192  2008      1    5        0         8.03        6            1   
11  193  2008      2    5        1         8.07        6            1   
12  194  2008      3    5        2         8.10        6            1   
13  195  2008      4    5        3         8.07        6            1   
14  196  2008      5    5        4         8.03        6            1   
15  192  2008      1    5        0         8.03        6            1   
16  193  2008      2    5        1         8.07        6            1   
17  194  2008      3    5        2         8.10        6            1   
18  195  2008      4    5        3         8.07        6            1   
19  196  2008      5    5        4         8.03        6            1   
20  192  2008      1    5        0         8.03        6            1   
21  193  2008      2    5        1         8.07        6            1   
22  194  2008      3    5        2         8.10        6            1   
23  195  2008      4    5        3         8.07        6            1   
24  196  2008      5    5        4         8.03        6            1   

      LoadNette  
0   53039.77133  
1   52200.71569  
2   51681.17260  
3   51907.94746  
4   50848.16566  
5   53039.77133  
6   52200.71569  
7   51681.17260  
8   51907.94746  
9   50848.16566  
10  53039.77133  
11  52200.71569  
12  51681.17260  
13  51907.94746  
14  50848.16566  
15  53039.77133  
16  52200.71569  
17  51681.17260  
18  51907.94746  
19  50848.16566  
20  53039.77133  
21  52200.71569  
22  51681.17260  
23  51907.94746  
24  50848.16566  

答案 1 :(得分:1)

pandas.sample function用于权重。语法:

#vec = <vector of rows weights>
df.sample(weights = vec)
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