{"action":"created","issue":{"url":"https://api.github.com/repos/python/mypy/issues/1529","repository_url":"https://api.github.com/repos/python/mypy","labels_url":"https://api.github.com/repos/python/mypy/issues/1529/labels{/name}","comments_url":"https://api.github.com/repos/python/mypy/issues/1529/comments","events_url":"https://api.github.com/repos/python/mypy/issues/1529/events","html_url":"https://github.com/python/mypy/issues/1529","id":154634541,"number":1529,"title":"builtins.property not accepted as a valid type for subclassing","user":{"login":"beckjake","id":452302,"avatar_url":"https://avatars.githubusercontent.com/u/452302?v=3","gravatar_id":"","url":"https://api.github.com/users/beckjake","html_url":"https://github.com/beckjake","followers_url":"https://api.github.com/users/beckjake/followers","following_url":"https://api.github.com/users/beckjake/following{/other_user}","gists_url":"https://api.github.com/users/beckjake/gists{/gist_id}","starred_url":"https://api.github.com/users/beckjake/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/beckjake/subscriptions","organizations_url":"https://api.github.com/users/beckjake/orgs","repos_url":"https://api.github.com/users/beckjake/repos","events_url":"https://api.github.com/users/beckjake/events{/privacy}","received_events_url":"https://api.github.com/users/beckjake/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-05-13T05:04:20Z","updated_at":"2016-05-13T05:13:28Z","closed_at":null,"body":"mypy doesn't like it when I subclass the builtin class `property`:\r\n\r\n```python\r\nclass blah(property):\r\n    pass\r\n```\r\n\r\nRunning mypy 0.4.1 or 9e4cfc8 against that file, I get:\r\n`test.py:1: error: Invalid type \"builtins.property\"`\r\n\r\nBut you totally can subclass property and build yourself a customized property decorator. \r\n\r\nLooking at some debugger statements it seems like the type has been classified as not being an instance of TypeInfo. I'm afraid I can't offer a PR to fix this because I have no idea where that should be happening."},"comment":{"url":"https://api.github.com/repos/python/mypy/issues/comments/218953602","html_url":"https://github.com/python/mypy/issues/1529#issuecomment-218953602","issue_url":"https://api.github.com/repos/python/mypy/issues/1529","id":218953602,"user":{"login":"gvanrossum","id":2894642,"avatar_url":"https://avatars.githubusercontent.com/u/2894642?v=3","gravatar_id":"","url":"https://api.github.com/users/gvanrossum","html_url":"https://github.com/gvanrossum","followers_url":"https://api.github.com/users/gvanrossum/followers","following_url":"https://api.github.com/users/gvanrossum/following{/other_user}","gists_url":"https://api.github.com/users/gvanrossum/gists{/gist_id}","starred_url":"https://api.github.com/users/gvanrossum/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gvanrossum/subscriptions","organizations_url":"https://api.github.com/users/gvanrossum/orgs","repos_url":"https://api.github.com/users/gvanrossum/repos","events_url":"https://api.github.com/users/gvanrossum/events{/privacy}","received_events_url":"https://api.github.com/users/gvanrossum/received_events","type":"User","site_admin":false},"created_at":"2016-05-13T05:13:28Z","updated_at":"2016-05-13T05:13:28Z","body":"Yeah, mypy probably only special-cases when the decorator is exactly\n'builtins.property'. :-(\n\nDo you have a work-around?\n"}}