尝试使用drop函数删除具有某些条件的行

Question

我试图删除具有特定值的行，我使用了drop函数，并将就地参数保持为True，但当我将数据帧写入新文件时，它不会被删除。

这是我的代码-

import pandas as pd
import numpy as np
assessment = pd.read_csv('/home/user/Documents/MOOC dataset new/students_Vle3_registration_info.csv')
assessment = assessment.values
i=0
n=[]
for assm in assessment[:,13:14]:
if(assm=='Withdrawn'):
n.append(i)
i=i+1
assessment = pd.DataFrame(assessment)
assessment.drop(n,inplace=True )
assessment.to_csv('/home/user/Documents/MOOC dataset new/students_Vle3_registration_info_withdraw_removed.csv')

我的代码出了什么问题？

Answer 1

如果没有太多信息，我宁愿使用矢量化方法：

import pandas as pd
assessment = pd.read_csv('/home/user/Documents/MOOC dataset new/students_Vle3_registration_info.csv')
condition = (assessment[col13].str.contains('Withdrawn')) | (assessment[col14].str.contains('Withdrawn'))
#col13 and col14 are the columns in your dataframe you are selecting by
assessment = assessment.drop(assessment[condition].index)