I have a two file. a.txt has the below data.

Zone,Aliase1,Aliase2
VNX7600SPB3_8B3_H1,VNX7600SPB3,8B3_H1
VNX7600SPBA_8B4_H1,VNX7600SPA3,8B4_H1
CX480SPA1_11B3_H1,CX480SPA1,11B3_H1
CX480SPB1_11B4_H1,CX480SPB1,11B4_H1

b.txt has the below data.

Zone,Aliase1,Aliase2
VNX7600SPB3_8B3_H1,VNX7600SPB3,8B3_H1
CX480SPA1_11B3_H1,CX480SPA1,11B3_H1

I want made result about compare two files zone columns like below.

Zone,Aliase1,Aliase2,Status
VNX7600SPB3_8B3_H1,VNX7600SPB3,8B3_H1,Active
VNX7600SPBA_8B4_H1,VNX7600SPA3,8B4_H1,Not used
CX480SPA1_11B3_H1,CX480SPA1,11B3_H1,Active
CX480SPB1_11B4_H1,CX480SPB1,11B4_H1,Not used

How can I make result. I tried using pandas. But I can't make result. please help me.

I think you need merge with outer join and parameter indicator=True and then rename column name and map 3 possible values (both, left_only and right_only):

#if no 'on' parameter, merge all columns
df = pd.merge(df1, df2, how='outer', indicator=True)
df = df.rename(columns={'_merge':'status'})
d = {'left_only':'Not used', 'both':'Active', 'right_only':'b_file_only'}
df['status'] = df['status'].map(d)
print (df)Zone      Aliase1  Aliase2    status
0  VNX7600SPB3_8B3_H1  VNX7600SPB3   8B3_H1    Active
1  VNX7600SPBA_8B4_H1  VNX7600SPA3   8B4_H1  Not used
2   CX480SPA1_11B3_H1    CX480SPA1  11B3_H1    Active
3   CX480SPB1_11B4_H1    CX480SPB1  11B4_H1  Not used

If you want compare only by Zone column add parameter on and filter in df2 column by subset ([[]]):

df = pd.merge(df1, df2[['Zone']], how='outer', indicator=True, on='Zone')
df = df.rename(columns={'_merge':'status'})
d = {'left_only':'Not used', 'both':'Active', 'right_only':'b_file_only'}
df['status'] = df['status'].map(d)
print (df)Zone      Aliase1  Aliase2    status
0  VNX7600SPB3_8B3_H1  VNX7600SPB3   8B3_H1    Active
1  VNX7600SPBA_8B4_H1  VNX7600SPA3   8B4_H1  Not used
2   CX480SPA1_11B3_H1    CX480SPA1  11B3_H1    Active
3   CX480SPB1_11B4_H1    CX480SPB1  11B4_H1  Not used