Use drop_duplicates
with parameter subset
, for keeping only last duplicated rows add keep='last'
:
df1 = df.drop_duplicates(subset=['A','B'])
#same as
#df1 = df.drop_duplicates(subset=['A','B'], keep='first')
print (df1)
A B C
0 1 2 x
2 3 4 z
3 3 5 x
df2 = df.drop_duplicates(subset=['A','B'], keep='last')
print (df2)
A B C
1 1 2 y
2 3 4 z
3 3 5 x