{"action":"created","issue":{"url":"https://api.github.com/repos/pydata/pandas/issues/11847","repository_url":"https://api.github.com/repos/pydata/pandas","labels_url":"https://api.github.com/repos/pydata/pandas/issues/11847/labels{/name}","comments_url":"https://api.github.com/repos/pydata/pandas/issues/11847/comments","events_url":"https://api.github.com/repos/pydata/pandas/issues/11847/events","html_url":"https://github.com/pydata/pandas/issues/11847","id":122331452,"number":11847,"title":"Unstack with mixed dtypes coerces everything to object","user":{"login":"potash","id":1166000,"avatar_url":"https://avatars.githubusercontent.com/u/1166000?v=3","gravatar_id":"","url":"https://api.github.com/users/potash","html_url":"https://github.com/potash","followers_url":"https://api.github.com/users/potash/followers","following_url":"https://api.github.com/users/potash/following{/other_user}","gists_url":"https://api.github.com/users/potash/gists{/gist_id}","starred_url":"https://api.github.com/users/potash/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/potash/subscriptions","organizations_url":"https://api.github.com/users/potash/orgs","repos_url":"https://api.github.com/users/potash/repos","events_url":"https://api.github.com/users/potash/events{/privacy}","received_events_url":"https://api.github.com/users/potash/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/pydata/pandas/labels/Bug","name":"Bug","color":"e10c02"},{"url":"https://api.github.com/repos/pydata/pandas/labels/Difficulty%20Intermediate","name":"Difficulty Intermediate","color":"fbca04"},{"url":"https://api.github.com/repos/pydata/pandas/labels/Dtypes","name":"Dtypes","color":"e102d8"},{"url":"https://api.github.com/repos/pydata/pandas/labels/Effort%20Low","name":"Effort Low","color":"006b75"},{"url":"https://api.github.com/repos/pydata/pandas/labels/Reshaping","name":"Reshaping","color":"02d7e1"}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":{"url":"https://api.github.com/repos/pydata/pandas/milestones/32","html_url":"https://github.com/pydata/pandas/milestones/Next%20Major%20Release","labels_url":"https://api.github.com/repos/pydata/pandas/milestones/32/labels","id":933188,"number":32,"title":"Next Major Release","description":"after 0.18.0 of course","creator":{"login":"jreback","id":953992,"avatar_url":"https://avatars.githubusercontent.com/u/953992?v=3","gravatar_id":"","url":"https://api.github.com/users/jreback","html_url":"https://github.com/jreback","followers_url":"https://api.github.com/users/jreback/followers","following_url":"https://api.github.com/users/jreback/following{/other_user}","gists_url":"https://api.github.com/users/jreback/gists{/gist_id}","starred_url":"https://api.github.com/users/jreback/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jreback/subscriptions","organizations_url":"https://api.github.com/users/jreback/orgs","repos_url":"https://api.github.com/users/jreback/repos","events_url":"https://api.github.com/users/jreback/events{/privacy}","received_events_url":"https://api.github.com/users/jreback/received_events","type":"User","site_admin":false},"open_issues":1022,"closed_issues":139,"state":"open","created_at":"2015-01-13T10:53:19Z","updated_at":"2016-08-19T13:17:00Z","due_on":"2017-08-31T04:00:00Z","closed_at":null},"comments":5,"created_at":"2015-12-15T18:08:24Z","updated_at":"2016-08-20T10:25:37Z","closed_at":null,"body":"Related to #2929, if I unstack a dataframe with mixed dtypes they all get coerced to object and I have to recast to go back which is surprisingly slow (30 seconds for 400k rows and 400 np.float32 columns)\r\n\r\nIs there any reason pandas doesn't keep the np.float32 dtype, especially since it supports missing values so even when there are missing index/column positions it shouldn't pose a problem?"},"comment":{"url":"https://api.github.com/repos/pydata/pandas/issues/comments/241192033","html_url":"https://github.com/pydata/pandas/issues/11847#issuecomment-241192033","issue_url":"https://api.github.com/repos/pydata/pandas/issues/11847","id":241192033,"user":{"login":"kordek","id":10603885,"avatar_url":"https://avatars.githubusercontent.com/u/10603885?v=3","gravatar_id":"","url":"https://api.github.com/users/kordek","html_url":"https://github.com/kordek","followers_url":"https://api.github.com/users/kordek/followers","following_url":"https://api.github.com/users/kordek/following{/other_user}","gists_url":"https://api.github.com/users/kordek/gists{/gist_id}","starred_url":"https://api.github.com/users/kordek/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kordek/subscriptions","organizations_url":"https://api.github.com/users/kordek/orgs","repos_url":"https://api.github.com/users/kordek/repos","events_url":"https://api.github.com/users/kordek/events{/privacy}","received_events_url":"https://api.github.com/users/kordek/received_events","type":"User","site_admin":false},"created_at":"2016-08-20T10:25:37Z","updated_at":"2016-08-20T10:25:37Z","body":"Picking this up to take a look"}}
{"actor":{"display_login":"kordek"}}