ValueError:传递的项目数错误2,展示位置暗含1

时间:2019-10-01 14:34:12

标签: python pandas valueerror

表格如下:

问题: 对于主题物理学,在所有被归类为误差在0-10%范围内的案例中,返回学生百分比大于或等于BSchool1(基准)中95%的学生百分比,错误范围是0-10%和学科物理。

[IN]

import pandas as pd
data = [['B1', 'Grade_physics', '0-10%', 70],['B1', 'Grade_physics', '10-20%', 5],['B1', 'Grade_physics', '20-30%', 25],['B1', 'Grade_Maths', '10-20%', 20],['B1', 'Grade_Maths', '0-10%', 60],['B1', 'Grade_Maths', '20-30%',20 ],['B2', 'Grade_Maths', '0-10%', 50],['B2', 'Grade_Maths', '10-20%', 15],['B2', 'Grade_Maths', '20-30%', 35],['B2', 'Grade_physics', '10-20%', 30],['B2', 'Grade_physics', '0-10%', 60],['B2', 'Grade_physics', '20-30%',10 ]]
df = pd.DataFrame(data, columns = ['BSchool Name', 'Graded in','Error Bucket','Stu_perc'])
df 
     [OUT]
       BSchool Name      Graded in      Error Bucket  Stu_perc
    0            B1  Grade_physics             0-10%        70
    1            B1  Grade_physics            10-20%         5
    2            B1  Grade_physics            20-30%        25
    3            B1    Grade_Maths            10-20%        20
    4            B1    Grade_Maths             0-10%        60
    5            B1    Grade_Maths            20-30%        20
    6            B2    Grade_Maths             0-10%        50
    7            B2    Grade_Maths            10-20%        15
    8            B2    Grade_Maths            20-30%        35
    9            B2  Grade_physics            10-20%        30
    10           B2  Grade_physics             0-10%        60
    11           B2  Grade_physics            20-30%        10

[IN]:

#Subset of values where error bucket and subject are sliced
filter1 = df['Graded in'].str.contains('Grade_physics')
filter2=df['Error Bucket'].str.contains('0-10%')
df2 = df[filter1 & filter2]

#Compare the value of student percentage in sliced data to benchmark value 
#(in this case student percentage in BSchool1) 
filter3 = df2['BSchool Name'].str.contains('B1')
benchmark_value = df2[filter3]['Stu_perc']
df['Qualifyinglist']=(df2[['Stu_perc']]>=0.95*benchmark_value)
[OUT]:
ValueError: Wrong number of items passed 2, placement implies 1
[IN]:
df['Qualifyinglist']=(df2['Stu_perc']>=0.95*benchmark_value)
[OUT]:
ValueError: Can only compare identically-labeled Series objects

我要做什么:

我们与B学校有合作关系,我们正在尝试预测每个B学校中学生的整体成绩。然后,我们尝试根据0-10%,10-20%等类别对预测不准确的情况进行分类。例如,对于商学院物理1,正确地识别了70%的情况,错误范围从0-在BSchool 1中,有10%,5%的案例预测的物理学误差在10-20%范围内,依此类推。我们在B学校1中的模型很成功。因此,我们希望看到我们现在可以定位到所有B学校。

但是我遇到了如上所述的错误。

Value Error:Wrong number of items passed 2, placement implies 1这对我没有帮助。请帮助

1 个答案:

答案 0 :(得分:0)

val=benchmark_value.iat[0]

df['Qualifyinglist']=df2['Stu_perc'].where(df2['Stu_perc']>=0.95*val)

这对我有用。