{"action":"created","issue":{"url":"https://api.github.com/repos/SciTools/iris/issues/1992","repository_url":"https://api.github.com/repos/SciTools/iris","labels_url":"https://api.github.com/repos/SciTools/iris/issues/1992/labels{/name}","comments_url":"https://api.github.com/repos/SciTools/iris/issues/1992/comments","events_url":"https://api.github.com/repos/SciTools/iris/issues/1992/events","html_url":"https://github.com/SciTools/iris/pull/1992","id":151705004,"number":1992,"title":"Remove deepcopies when slicing cubes and copying coords","user":{"login":"rhattersley","id":917914,"avatar_url":"https://avatars.githubusercontent.com/u/917914?v=3","gravatar_id":"","url":"https://api.github.com/users/rhattersley","html_url":"https://github.com/rhattersley","followers_url":"https://api.github.com/users/rhattersley/followers","following_url":"https://api.github.com/users/rhattersley/following{/other_user}","gists_url":"https://api.github.com/users/rhattersley/gists{/gist_id}","starred_url":"https://api.github.com/users/rhattersley/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rhattersley/subscriptions","organizations_url":"https://api.github.com/users/rhattersley/orgs","repos_url":"https://api.github.com/users/rhattersley/repos","events_url":"https://api.github.com/users/rhattersley/events{/privacy}","received_events_url":"https://api.github.com/users/rhattersley/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":17,"created_at":"2016-04-28T17:57:08Z","updated_at":"2016-05-11T16:00:51Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/SciTools/iris/pulls/1992","html_url":"https://github.com/SciTools/iris/pull/1992","diff_url":"https://github.com/SciTools/iris/pull/1992.diff","patch_url":"https://github.com/SciTools/iris/pull/1992.patch"},"body":"An updated version of #939.\r\n\r\n_Not ready for merging..._\r\n\r\n...the remaining [open question](https://github.com/SciTools/iris/pull/939#issuecomment-117273736) is whether being able to switch this change on/off with a `Future` toggle out-weighs the implementation leakage."},"comment":{"url":"https://api.github.com/repos/SciTools/iris/issues/comments/218505664","html_url":"https://github.com/SciTools/iris/pull/1992#issuecomment-218505664","issue_url":"https://api.github.com/repos/SciTools/iris/issues/1992","id":218505664,"user":{"login":"pp-mo","id":2089069,"avatar_url":"https://avatars.githubusercontent.com/u/2089069?v=3","gravatar_id":"","url":"https://api.github.com/users/pp-mo","html_url":"https://github.com/pp-mo","followers_url":"https://api.github.com/users/pp-mo/followers","following_url":"https://api.github.com/users/pp-mo/following{/other_user}","gists_url":"https://api.github.com/users/pp-mo/gists{/gist_id}","starred_url":"https://api.github.com/users/pp-mo/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pp-mo/subscriptions","organizations_url":"https://api.github.com/users/pp-mo/orgs","repos_url":"https://api.github.com/users/pp-mo/repos","events_url":"https://api.github.com/users/pp-mo/events{/privacy}","received_events_url":"https://api.github.com/users/pp-mo/received_events","type":"User","site_admin":false},"created_at":"2016-05-11T16:00:51Z","updated_at":"2016-05-11T16:00:51Z","body":"> I'm not sure we're ready to force this into v1.10\r\n\r\nI took a look into how to document/explain this, and was rather taken aback by some of the **existing** behaviour.  I had thought we consistently avoided view-like copies in Iris up to now, but that is not the case for coords as it turns out .\r\nWould you believe...\r\n```\r\n>>> from iris.coords import AuxCoord\r\n>>> co1 = AuxCoord([1,2,3,4,5])\r\n>>> co2 = co1.copy()\r\n>>> co2.points[2:4] = 77\r\n>>> co2\r\nAuxCoord(array([ 1,  2, 77, 77,  5]), standard_name=None, units=Unit('1'))\r\n>>> co1\r\nAuxCoord(array([1, 2, 3, 4, 5]), standard_name=None, units=Unit('1'))\r\n>>> \r\n>>> co3 = co1[:]\r\n>>> co3.points[1:3] = -99\r\n>>> co3\r\nAuxCoord(array([  1, -99, -99,   4,   5]), standard_name=None, units=Unit('1'))\r\n>>> co1\r\nAuxCoord(array([  1, -99, -99,   4,   5]), standard_name=None, units=Unit('1'))\r\n```\r\nSo [:] delivers a new coord with a view on the old one after all.\r\n\r\nThis could make it harder to explain what we are changing."}}