I have a dataframe which looks like this:

```
time text
01.01.1970 abc
01.01.1970 cde
01.01.1970 fgh
01.01.1980 abc
01.01.1980 xyz

```

I would like to join the content in `text` based on column `time`. I want to join them separated by `\n`. How can I do this in order to get such a dataframe?

```
time text
01.01.1970 abc\ncde\nfgh
01.01.1980 abc\nxyz

```

I tried the following but I do not get what is expected but instead for every row in `text` I get: `text\ntime`.

```
out = (df.groupby('time', as_index=False)
       ['text'].agg(lambda x: '\n'.join(x.dropna())))

```