How to check if the value is present in df for multiple columns and append if not present

I have multiple df and i want to compare one with the other if the values are same. And if values are not same i want to append the value to the first data frame. For example: data frame 1

A	B	C
Mm	hh	jj
Kk	ll	gg

Data frame 2 | A | B | C | |—|—|—| | Oo|ii |ff | | Mm|hh |jj |

Final df | A | B | C | |—|—|—| | Mm|hh |jj | | Kk|ll |gg | | Oo|ii |ff |

Also i want to compare all the columns

Answer

Use pd.concat to combine the two data frames and then apply drop_duplicates method to remove all the duplicate rows

final = pd.concat([df1, df2], axis=0).drop_duplicates().reset_index()