Good evening,

I would like to know, which is the best way to compare two dataframes and return a combination of them? Or if there's even a build-in function inside pandas?

For example, these are my two dataframes:

**Dataframe 01:**

```
first_name | age | id | value_a | value_b | value_c
peter      | 37  | 19 | 4562    | 78      | 21.5
jane       | 32  | 5  | 3832    | 85      | 17.0
michael    | 43  | 41 | 2195    | 63      | 44.4

```

**Dataframe 02:**

```
first_name | age | id | value_a | value_b | value_c
sarah      | 51  | 2  | 63      | 81      | 4.1
peter      | 37  | 19 | 4562    | 81      | 21.5
tom        | 22  | 89 | 107     | 14      | 0.0
michael    | 43  | 41 | 1838    | 63      | 44.4

```

As you can see, there are some new entrys troughout the whole dataframe (Dataframe 02) and some of the already existing ones are also listed --> some changes were made in these rows!
What I want to achieve is a new(?) dataframe that contains all the new rows, the already existing ones and those who got updated! In this case:

**Dataframe New**

```
first_name | age | id | value_a | value_b | value_c
peter      | 37  | 19 | 4562    | 81      | 21.5
jane       | 32  | 5  | 3832    | 85      | 17.0
michael    | 43  | 41 | 1838    | 63      | 44.4
sarah      | 51  | 2  | 63      | 81      | 4.1
tom        | 22  | 89 | 107     | 14      | 0.0

```

**Notes:**

* there is always a column (here: 'id') that can be seen as a non changing key
* the amount of rows may differ
* the amount and names of the colums are always staying the same
* the order of the rows is not important

Thanks for all your help and a great evening!