Possibly unexpected behaviour when using apply and custom funcs
```
total=pd.DataFrame({"all_eternal":[1,2,1,1,0,1],"country_name":["United States","Germany","Germany","Germany","France","United States"],"amount":[20,40,30,10,5,6]})
```

When I apply

```
totalbycountrynew=total.groupby(["country_name"],as_index=False).apply(
        lambda g:
            pd.Series({
                    "LTVav":g.amount.mean(),
                    "LTVav_without_trials":g.amount[g.all_eternal!=1].mean()
                    })
        )
```


I would like to see:

```
country_name	LTVav	LTVav_without_trials
France	          5.0                         5.0
Germany	         26.7                       40.0
United States	13.0	                       nan
```

Instead I see:
```
LTVav	LTVav_without_trials
 5.0                         5.0
 26.7                       40.0
 13.0	                       nan (with index 0,1,2)
```

Without as_index=False works as_expected - countries' names are there, but they are in index
While there is a workaround, I would say it is an unexpected behaviour (at least non-intuitive one)

(sorry for styling, I don't know Markdown)