[英]Sum values of columns that start with the same text string
I want to take the sum of values (row-wise) of columns that start with the same text string.我想获取以相同文本字符串开头的列的值的总和(按行)。 Underneath is my original df with fails on courses.下面是我原来的 df 课程失败。
Original df:原始df:
ID P_English_2 P_English_3 P_German_1 P_Math_1 P_Math_3 P_Physics_2 P_Physics_4
56 1 3 1 2 0 0 3
11 0 0 0 1 4 1 0
6 0 0 0 0 0 1 0
43 1 2 1 0 0 1 1
14 0 1 0 0 1 0 0
Desired df:所需的df:
ID P_English P_German P_Math P_Physics
56 4 1 2 3
11 0 0 5 1
6 0 0 0 1
43 3 1 0 2
14 1 0 1 0
Tried code:试过的代码:
import pandas as pd
df = pd.DataFrame({"ID": [56,11,6,43,14],
"P_Math_1": [2,1,0,0,0],
"P_English_3": [3,0,0,2,1],
"P_English_2": [1,0,0,1,0],
"P_Math_3": [0,4,0,0,1],
"P_Physics_2": [0,1,1,1,0],
"P_Physics_4": [3,0,0,1,0],
"P_German_1": [1,0,0,1,0]})
print(df)
categories = ['P_Math', 'P_English', 'P_Physics', 'P_German']
def correct_categories(cols):
return [cat for col in cols for cat in categories if col.startswith(cat)]
result = df.groupby(correct_categories(df.columns),axis=1).sum()
print(result)
Let's try groupby with axis=1:让我们尝试使用axis = 1的groupby:
# extract the subjects
subjects = [x[0] for x in df.columns.str.rsplit('_',n=1)]
df.groupby(subjects, axis=1).sum()
Output: Output:
ID P_English P_German P_Math P_Physics
0 56 4 1 2 3
1 11 0 0 5 1
2 6 0 0 0 1
3 43 3 1 0 2
4 14 1 0 1 0
Or you can use wide_to_long
, assuming ID
are unique valued:或者您可以使用wide_to_long
,假设ID
是唯一值:
(pd.wide_to_long(df, stubnames=categories,
i=['ID'], j='count', sep='_')
.groupby('ID').sum()
)
Output: Output:
P_Math P_English P_Physics P_German
ID
56 2.0 4.0 3.0 1.0
11 5.0 0.0 1.0 0.0
6 0.0 0.0 1.0 0.0
43 0.0 3.0 2.0 1.0
14 1.0 1.0 0.0 0.0
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.