Python 比较两个不同的 CSV 文件哪些值不在同一行中

Question

I have 2 CSV File which are looking like that:

first.csv (MasterFile)

Test1  10
Test2  20

second csv

Test8  80
Test1  10

In this case i'd like to create a function which says if value (Test8) in second.csv doesn't exists in first.csv print False.

My Code:

def checkContent():
    masterFile= pd.read_csv('./first.csv', error_bad_lines=False)
    df1=pd.DataFrame(masterFile, columns=[1])
    customerFile=pd.read_csv('.second.csv', error_bad_lines=False)
    df2=pd.DataFrame(customerFile, columns=[0])

    df1[1] = df2[0]
    check=np.where(df1[1]==df2[0], True, False)
    print(check) 

But it just compares the first row. Not the other rows. I know that it has to be done by row += 1 or something like that

Answer 1

IIUC you need a left join with indicator = True

check = np.where(pd.merge(df2,df1,on=['A','B'],how='left'
         ,indicator=True)['_merge'] == 'left_only',
         False,
         True)

print(check)
array([False,  True])

---

print(pd.merge(df2,df1,on=['A','B'],how='left',indicator=True))

       A   B     _merge
0  Test8  80  left_only
1  Test1  10       both