Answers for "pandas merge without duplicate columns"

concatenate dataframes pandas without duplicates

>>> df1
   A  B
0  1  2
1  3  1
>>> df2
   A  B
0  5  6
1  3  1
>>> pandas.concat([df1,df2]).drop_duplicates().reset_index(drop=True)
   A  B
0  1  2
1  3  1
2  5  6

pd.merge duplicate columns remove

#Create test data
df1 = pd.DataFrame(np.random.randint(100,size=(1000, 3)),columns=['A','B','C'])
df2 = pd.DataFrame(np.random.randint(100,size=(1000, 3)),columns=['B','C','D'])

pd.merge(df1, df2, how='inner', left_on=['B','C'], right_on=['B','C'])