{"action":"created","issue":{"url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/447","labels_url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/447/labels{/name}","comments_url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/447/comments","events_url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/447/events","html_url":"https://github.com/MDAnalysis/mdanalysis/issues/447","id":108292143,"number":447,"title":"atomgroup object can forget about positions","user":{"login":"kain88-de","id":4302678,"avatar_url":"https://avatars.githubusercontent.com/u/4302678?v=3","gravatar_id":"","url":"https://api.github.com/users/kain88-de","html_url":"https://github.com/kain88-de","followers_url":"https://api.github.com/users/kain88-de/followers","following_url":"https://api.github.com/users/kain88-de/following{/other_user}","gists_url":"https://api.github.com/users/kain88-de/gists{/gist_id}","starred_url":"https://api.github.com/users/kain88-de/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kain88-de/subscriptions","organizations_url":"https://api.github.com/users/kain88-de/orgs","repos_url":"https://api.github.com/users/kain88-de/repos","events_url":"https://api.github.com/users/kain88-de/events{/privacy}","received_events_url":"https://api.github.com/users/kain88-de/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-09-25T09:30:10Z","updated_at":"2015-09-25T12:59:53Z","closed_at":null,"body":"I stumbled onto something very strange\r\n\r\nThis code snippet will result in `__getattr__` to throw\r\n\r\n```python\r\nsel = mda.Universe(PDB).select_atoms('name CA')\r\nsel.positions\r\n```\r\n\r\nHowever this snippet works as expected.\r\n\r\n```python\r\nu = mda.Universe(PDB)\r\nsel = u.select_atoms('name CA')\r\nsel.positions\r\n```\r\n\r\nboth snippets used to work in `0.10.0`"},"comment":{"url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/comments/143215092","html_url":"https://github.com/MDAnalysis/mdanalysis/issues/447#issuecomment-143215092","issue_url":"https://api.github.com/repos/MDAnalysis/mdanalysis/issues/447","id":143215092,"user":{"login":"mnmelo","id":11721337,"avatar_url":"https://avatars.githubusercontent.com/u/11721337?v=3","gravatar_id":"","url":"https://api.github.com/users/mnmelo","html_url":"https://github.com/mnmelo","followers_url":"https://api.github.com/users/mnmelo/followers","following_url":"https://api.github.com/users/mnmelo/following{/other_user}","gists_url":"https://api.github.com/users/mnmelo/gists{/gist_id}","starred_url":"https://api.github.com/users/mnmelo/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mnmelo/subscriptions","organizations_url":"https://api.github.com/users/mnmelo/orgs","repos_url":"https://api.github.com/users/mnmelo/repos","events_url":"https://api.github.com/users/mnmelo/events{/privacy}","received_events_url":"https://api.github.com/users/mnmelo/received_events","type":"User","site_admin":false},"created_at":"2015-09-25T12:59:53Z","updated_at":"2015-09-25T12:59:53Z","body":"Well, I would definitely not classify it as a bug, since we foresaw it and discussed whether to change the API in this respect or not.\r\n\r\nNomenclature aside I think you make the case to reopen that discussion. @richardjgowers, @orbeckst, and myself had no conflicting use of the Universes when the issue was brought up. The question is now whether to uphold the API change (and certainly better document it), revert it (we have to think what that entails, since it's linked to AtomGroup picklability), or something in between (doing our own AtomGroup-to-Universe bookkeeping?)."}}