def item( was broken
`pd.DataFrame({"a":[1,2,3]}).a.item() ` -- breaks! 
`pd.DataFrame({"a":[1,2,3]}).a.values.item(0)` --- this is actual expected behaviour

- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

@avloss this has been the behaviour as long as it existed I think. Numpy supports `item()` without argument as well. It means that it only works for objects with length 1 and otherwise raise.  

It could make sense to actually pass through the argument, but since this method is deprecated, I don't think we should still make improvements to the method. Yea I think this method needs to be removed altogether for 1.0 (ref #6581) - @avloss are you interested in cleaning that up? As mentioned this is a deprecated method so I don't think we have an appeatite for this. In any case thanks for the PR! If you'd like to contribute would certainly take the actual removal of this method altogether